anyone else mess up their basement reno big time?

Started redoing our basement about two months ago, and honestly... kinda regretting some choices already. Thought it'd be easy enough to figure out as we went along (thanks YouTube), but turns out there's a lot more to it than just slapping drywall up and adding flooring.

We totally forgot about moisture management, and now we're noticing this musty smell. Also, lighting - we went with recessed lights but didn't space them out properly, so it looks weirdly dark in some spots and way too bright in others. And don't even get me started on outlets...why did no one tell me you can never have too many?

Anyway, before we make things worse (or spend even more money fixing stuff), figured I'd ask here first. Maybe save someone else from making the same expensive mistakes, lol. What are some of the biggest things you overlooked or wish you'd known before tackling your basement?