Actually it does not matter what you want to write, because the problem and solution are always the same.
What is holding you back is not that you do not know how to write a character waking up in first person, or not that alone, but that you are not used to writing. You feel like a person that steps on a diving tower for the first time and finds that from up there the water looks very far away. You hesitate, because you are afraid of failure.
So the first thing you need to do is "lower that diving board". You must make writing something normal and unremarkable, like brushing your teeth. And how do you do that? By making it a habit. I have gone into making writing a habit in three other answers of mine. Look at them: one, two, and three. In short, to be able to write that beginning, you need to write regularly for some time.
If you think that, well, you are trying to write regularly but are stuck on the beginning, then I suggest that you write anything at all. The high diver doesn't begin from ten meters, but from the side of the pool. Only when he is used to jumping in the water from the side of the pool does he get up on the one meter board. Do the same. Write anything at all. Whatever you have in your mind. Every day. And even once you are used to writing regularly, you might not want to dive right in on most days. Sportsmen don't begin their training by breaking a world record, but by warming up. Draughtsmen don't begin their workday by pencilling a wonderful artwork, but by doing warmups. Many writers warm up by just writing down whatever comes to their minds. After fifteen to thirty minutes you will find that your thoughts are beginning to take shape, that your words flow more easily, and that you are ready to write in earnest. Begin your days work then.
Finally, do not be afraid of failure, or, in other words, don't expect too much from your first attempt at writing a novel (or other story). Writing is something that you must learn, like any other skill. If you expect your first attempt to be perfect, you will never write that beginning, because you will never feel ready for it. What I suggest you do is write that first scene in any way at all. It does not matter if it is well written or not, it only matters that you write it and keep writing. You can come back and revise it one you have it on paper or you can throw it away and write the next novel. It really doesn't matter, because you have about 10,000 hours of writing to do before you get published anyway, so you better start and stop hesitating now.
Now that you are in the right frame of mind and ready to begin, lets pause for a moment and look at what you might actually do to make that first scene as good as you can. So how do you write someone waking up from the first person perspective? That's quite easy and simple.
What you do is remember how waking up feels for you, and write that down.
Yes, that's all. You have woken up countless times in your life, and you are an expert at waking up. All you need to do is write down how you experience that. Easy as pie. What is the first sensation? The first thought? Are you fully conscious and ready to jump on an unbroken horse, or are you befuddled and need a gallon of coffee before you can even open your eyes to the painfully bright light from your bedside clock? Do you wake up from the sound of your dad coughing up blood, or do you discover the blood smears when you want to brush your teeth?
Just write it down in any way at all. Then either rewrite it, or write on.