I think isn't good for a 12 year old to be seriously dating. It's okay though, as long as it's not too serious. It's good practice on charming girls, learning how to please them, and getting more comfortable around them. At that stage, you are just out of the "Cooties" thing, and it should take some time to fully lose it. When I was in middle school, you were crazy if you didn't have a girlfriend.