Submissions are closed in 8 hours, I strongly recommend you upload what you have anyway - even if it's unfinished :) there are a ton of people in the same position, don't worry too much about it. 

It's up to you, of course, but by uploading what you'll have you'll get a bunch of feedback on what's there, and you'll get used to the build process, itch's upload system and what to do when writing an Itch page! Definitely worth it.