Speaking about retopo @superchaton
If you have some extra dough just lying around and thinking about throwing it in the trash you could get Quad Remesher license for a decent quick and dirty retopo/remesh. It will get you a decent amount of progress on the retopo before you need to make adjustments.
Or you could use free tools like InstantMesh or the built-in quad remesher, or you just totally go all in and do everything by hand (I have done this a few times).
Retopoflow is a great add-on as well but also on the pricey side. I have both of these and love them.
Also: I highly recommend to make a copy of your model for safe keeping before doing retopo, that is always my recommendation.
