Hi, yesterday I downloaded OSM and when I started it, it made me create a new account (just a new name), but I have already an other account that I made years ago, how can I change account? (I mean in the app). If I touch on the name it asks me the email (that I've already verified) and in the settings there's no way to change account
Having more than one account on OSM is against the rules. You should play with same account on all platforms.
If you want to keep the new account, just delete the other one on web version! If you want to play with the old one also on the APp, delete the new one on WEB and contact our support so they can help you switching accounts on App!