For me, if I can't think of a good name for a character (or for that matter any other world element), I hold off on naming it. Instead, I give it a temporary name. Anything that is reasonably easy to type and remember, yet not too likely to show up in the text otherwise, works. The first priority for me here is to not lose momentum just because I can't think of a name for something at the spur of the moment. That's what editing is for.
One good tip I saw somewhere (but I have since forgotten where) is to mark such temporary names with a typeable character which won't appear elsewhere, and which you use consistently for that purpose. For example, you might mark them with an = sign as either a prefix or a suffix.
For me, I'll often turn to the NATO phonetic alphabet for ideas if I'm pressed for a name for something that is in-progress and for which I need a name right now. (Not least of which because it's a good 26 distinct words which I have memorized already.) Not all of those words are good names, and which ones actually work will depend on the story you're writing, but many of them are workable. You can probably easily get a dozen decent temporary names out of those.
Combining those two, while writing and needing a name right off the bat, I might type
=Juliett and keep writing. Afterwards, while editing, I'll search for all occurences of
= which will point me to the fact that I've used
Juliett as a temporary name, and I'll also search for that to find all places where I've used it as a name. That makes giving (say) the character its final name little more than an exercise in search-and-replace, once I know what to name them, but doesn't put the pressure on me to name them at the moment they are first introduced.
Another thing I'll often do is to, while reading, maintain a running list of name ideas. This doesn't need to be anything fancy, and could just be a text file or a physical notebook. In it, I jot down whatever idea I see for a name, a brief note about its context and any meaning attached to it, and where I saw it (so I can go back and look it up again if necessary). When I need a name, I'll bring that list out and browse through it until I spot something that fits. I might end up using that name as-is, or I might end up tweaking it, but the name ideas list is a go-to resource when I need a name for something, be it a character, a country, a planet, or a species, and can spare the time to browse through the list.