bitcoin on cashapp!

Hi! I’ve always wanted to buy stocks and or invest? i’m not sure what the right terminology is, i’m currently 17 and not in school. I work around 25 hrs a week and get paid minimum wage (15/hr) half of my paycheck goes to my mom and I keep the rest. I just bought 86 dollars in bitcoin through the cashapp app, is it bad to use that app? Or does it work fine, I’ve tried other apps in the past but it’s kind of a lot of work to set up because i’m underage. I’m not really sure what i’m doing but I saw another thread and someone said that buying bitcoin is a way to save your money, so that’s where I decided to keep my savings. But i’m wondering if I should use a different app or if it doesn’t matter. Any replies would be appreciated ^{_^}