"Writing is rewriting... If you fall in love with the vision you want of your work and not your words, the rewriting will become easier." - Nora DeLoach
I love that quote. The first draft is about getting the story down that you want to tell. The words might not be the right ones. The scenes might not be the right ones. The characters may be flat and dull. But it's okay. Write because you have a story to tell and fall in love with that story. Later, you will revise to take care of all those things.
Just get the story down - and let yourself fall in love with it.
I've been writing 1,000 words a day on my WIP. Sometimes I go back and tinker with earlier chapters, and I know some writers don't let themselves do that because they'll do that forever. But for ME, that tinkering often helps me get back into the story - back into the world that can be hard to reenter at times.
That's the thing about first drafts. We have to figure out what works for each of us. I've learned what works for me. I now know I can do 1,000 words a day pretty easily in an hour or two, if I open the document, read some of the previous day's work, tinker if necessary, and start writing.
I also know that the reentry is easiest if I leave off in the middle of a scene, in a place where I can pick right up and keep going. Sometimes I leave myself notes to remind myself what I want to happen. But I now know it's so much easier to get writing when I've left off in the middle of something rather than the beginning of a new chapter. Blank pages are HARD, so I try to avoid them as much as possible when writing a first draft.
Figure out what works for you. Write to get the story down. Remember, it's YOUR story in the first draft. Don't worry about anyone else. Write for yourself. Fall in love with it.
There's plenty of time later to do the work to make other people fall in love with it.