In my story, my characters have to go on a journey, plus it's medieval. (So original right?) Anywho, they've already been captured by road robbers once and escaped. Also, they've stumbled upon a town and acquired a new member to their party. I'd like for the three to bond but... What else can happen to them before they reach their destination? I know a bunch of boring camping scenes is not the way to go, so what is?
I'm not going to tell you how to solve your problem. Quite frankly, I don't know how to solve your problem, despite having faced it countless times myself in the past. Instead, I'm going to show you why you have this problem in the first place. I'm going to show you how to treat the cause instead of the symptoms.
Not knowing what to include in your novel is a sign that you don't know what your novel is about. It sounds strange, I know, so allow me to explain.
Your novel needs to be about something. Contrary to seemingly-popular belief, you cannot just write a cool plot and leave it at that. There will be gaps, such as boring journeys, that are not covered by the 'cool plot' (amongst other things).
Think of it this way: what are you trying to accomplish with your novel? I'm not talking about publishing here, I'm talking about your own goals. Are you writing just to get a story out on paper? Are you maybe writing just to see if you can? Or are you actually trying to say something through your writing?
If you are trying to say something, then take that message (called a theme by some), and craft your story around it. Theme will tell you what kind of story you want to write, if you look at it closely enough. It will tell you what kind of characters will get the theme across to the reader. It will tell you what kind of plot will vault the theme from beginning to end, to that very moment in the climax where the reader suddenly realizes what you're trying to tell him.
If you know this, you will never be faced with what I like to term the 'awkward journey' or anything similar. You will always know where you are going, why you are going there, and how to get there.
If you find yourself facing an 'awkward journey,' think about why. Is this truly part of what the theme told you to do? Or are you simply including it because it is 'cool' or a chance to show off your medieval world? Write your story from the theme alone, and every single scene will have a purpose.
P.S. More directly related to your dilemma: I find myself often faced by awkward journeys, despite the story coming straight from the theme. When this happens, it is usually because I had a vague idea of what I wanted the story to be like before I considered the theme, and then that idea found its way into the plot. You can fix this by asking yourself if those two people really need to be apart. Does that city really have to be that far away? Is an entire journey necessary, or will the same thing be accomplished by the protagonist going two houses to the right and knocking on the front door? Watch your plot. It may seem like letting it take its own route is a good idea, but it's not. At least not until you know where it should go from beginning to end. Trust me; I've been there too many times.
Your goal, as the author, is for the characters to bond over the journey.
But what is your reader reading for?
Your reader doesn't know that the characters are meant to bond by the journey's end. They might not even care, at this point, about the characters bonding. You've given the reader one thing to look forward to, one milestone he knows is the next step in the "actual" plot: the destination they're headed for.
That means that any delay that doesn't seem like part of the "actual" plot, basically feels like marking time. An unnecessary delay. You can have obstacles on the path - but unless you make them important obstacles, with greater significance for the overall story, then the reader's basically just waiting for them to be over.
So the question you need to answer is: What is your reader reading the journey for? If you gave your reader the option to skip right ahead to the destination -- does he know any good reason not to take it? Or does he just need to take it on faith that something interesting will happen, and he has no idea what that might be?
Let me toss out a few possible answers to that question. Not "here's what you should do"; just some examples demonstrating different approaches.
The obstacles on the road form a contained plot arc.
For example, "The area is battle-torn and the destination is under siege." Or "The characters are accompanying a travelling circus, and one of the circus crew is murdering the others one by one."
This gives you, right from the start of the journey, some clear conflicts, tension, and milestones to look forward during the journey. It might be entirely unrelated to the rest of the story, but it serves the purpose of making the journey interesting, significant, with a clear arc.
A major plot element is also affecting the journey.
For example, if the book is about fighting the evil Medusa Emperor, than the journey might take the characters through towns taken over by the Medusae, or they're hounded by a Medusa commander who knows they're a threat. If it's about how magic is fading from the world, maybe there's a town impoverished because they've run out of magic power, maybe the King is collecting a "magic tax" along the road, or maybe the characters are chased by a wizard who thinks they have a rare remaining powerful artifact.
Here, you don't need an entire plot arc just for the journey. Instead, every time something happens, the reader knows it's important because it ties in to what's already important to the story at large. This gives you a chance to work in different angles and aspects of your primary plot strands.
The interaction between the characters is what's interesting.
It's quite possible that the journey is uneventful, except the real drama is what happens between the characters on the road. One's in love with the other; one's trying to figure out the other's dark secret; one's trying to convert the other to his religion; what-have-ye.
This can be a subplot, like the first case ("We only have until Tiramisu City to convince him, brother!"), or it can be a boiling point for an overarching conflict ("I was perfectly in control of myself before I spent a month by your side, my beloved!").
Either way, you're simply building up an ongoing arc of developments advancing the interpersonal plot. Say, first the prisoner tries to escape; then one of the captors needs to guard him extra-close; since there's so close, the prisoner starts learning some private, personal details... Have a progression. And make sure that every major step of the progression holds some promise and appeal to the reader, right from the start - that things are going to be interesting; that something's about to change.
As long as you know what purpose your journey-time is serving, all you need to do is move that purpose further.
You can mix and match between these - the story can do multiple things at once. You can have development between the characters and a subplot for the the journey ("Are Bob's infuriating prayers keeping the vampires away, or keeping them following us?"). That might be what you want here - some external action, which will also provide material for your bonding arc.
But whatever you choose, tie it in to a larger arc. Keep to a minimum episodic, "random" encounters - the kind of obstacles that the reader has no vested interest in, and that leave the protagonists in exactly the same state they were beforehand. One every now and then is OK - dangerous, surprising stuff happens - but don't let the reader feel like you're treading water, or marking time until there's been "enough bonding."
One last option is that there isn't anything interesting on the journey. Not enough to sustain the amount of writing you want, for a sense of time, a gradual progression.
In that case, consider cutting the journey out entirely.
This requires some juggling, but it's very doable. It means that anything important you were planning to portray over the journey, needs to be moved to before, or after, or to be flashbacked to, or infodumped... But you've got options. Don't get locked into one thing just because it's the most intuitive, without considering if maybe there are other ways to solve this that will solve your problem entirely.
This is a question I've asked many a time myself. I'm also writing a fantasy/medieval story and I've struggled with this to the point that I just skip writing these traveling scenes (which you shouldn't do; it's essential to show time and distances have been passed/covered).
Depending on what voice you're using (first person, third person, etc.), I would fill in some of the gaps with dialogue and thoughts of your MC(s). This can be used to develop your character(s), mostly by leaving them alone with their thoughts!
Also, it never hurts to add a LITTLE description of passing scenery of villages if you make it interesting enough, an odd tree, mountains in the distance. It's also a good idea (if they're traveling for some time) to include a campsite, a place when your characters rest, and include them being tired and sore. Possibly to make it more interesting one of them can be hurt and have trouble traveling at the same pace as the others; he/she could get better or worse and this could add some tension! Will this character live??
If all else fails and you've got no idea how to add excitement, make a character suffer. TENSION!!! :)
Also don't stretch it out too long because even if your characters are being hunted with an injured companion and no hope of escape, making them travel hopelessly for too long will get extremely boring!
It's also a good idea to add a character plot twist - a secret of some sort that is revealed about one of your characters and makes your other characters think differently about this character. (Yes, I know I said character four times, wasn't sure how to put it so it could make sense. Hope this helps! :) )