I'm not sure if you've already got some music for the game in mind, but you may want to get in touch with 'SpaghettiLord1010#2985' on my Discord and see if any of their public free music might suit the ambiance of your game.
They're also a gamedev and have struggled with getting noticed online. Making a career-shift to audio engineering was a really fantastic move for them :)
Do what you feel works for you and as always if you require help don't be afraid to ask for it. Advice, tips, links, etc. One thing I learned as an adult is that a 'real' adult is someone who isn't afraid to ask for help when needed. Trying to do everything solo is a recipe for burnout.