Yeah some clients will do weird stuff like that. Make sure you aren't copying your nsec key to apps you don't fully trust. That's equivalent to giving your password. Some will let you login in a read only mode with your npub, that's like your username. That way you can kind of see how your profile would look there, but it can't change anything. It may be best for you to setup a test account for playing around with until you trust things and get the hang. I know it is a bit overwhelming! 🤯