I would say write it out and publish it and keep going with it. If later on you go back to it and decide you don’t really like how it starts, rewrite it and have it seam with the other chapters already written. I totally understand though, there are some chapters where I rewritten a couple of times because I don’t like how it sounds.
I also like to make a little private doc where I right the main story plot, and smaller details so I have a base of what I want… if that makes sense lol