have lots of time

That's all you need. Pick an instrument and buy a cheap example, and use YouTube tutorials as your coach. My parents have gone from zero piano knowledge to banging out a few classics in about a year even though they barely have any time to practice at all.

If you're looking for something more structured, classes and lessons are good too. I used to take guitar lessons and though I don't anymore, I played a lot better back then because I was constantly being pushed to practice and learn new stuff. Don't feel like you have to stick with the first instructor you find though, sometimes you'll start lessons and just not "click" with the person teaching you, if that happens let the month (or however many you paid for) run out and try again with someone else.

The hardest thing is going to be forcing yourself to practice instead of, idk, browsing the internet or however else you're currently spending your time. You've gotta find a way to get into the mindset that grinding out practice is fun, or at least more interesting than the alternative, otherwise you'll do what I'm currently doing and end up with a bunch of nice musical kit in your room that you never use.

Come to think of it, I used to really like playing Rocksmith, so if you're interested in the guitar that's my app recommendation. Ubisoft is currently pushing Rocksmith+, which is a subscription service that replaced the main game - but you can still buy (or 🏴‍☠️) Rocksmith 2014 and mod in community-made songs. If you go down this route this is the website where you can get them.