Try this, it worked for me. I am a little to young for the game also but I do have to ask you a question to continue. Do one of your parents/guardians have a microsoft account so you can change your privacy? If they do then continue reading this. Okay so if your parent/guardian has an acount ask them to sign in. Once they sign in go to the Xbox One dashboard and click onthe profile. You will see a couple of options such as, Appear offline, Friends, and so on. Scroll to the bottom and you will see Privacy Settings, click on that. Scroll to the right and you will see your Xbox Live account, click on your account and there should be a Privacy button or something along the lines of that. Click on it and you should be faced with a couple of options, Child, Teen, Adult, and Custom. You want to go onto Custom. While you are in Custom some things should say Block. Change all the blocked ones to say Allow and it should not tell you that you are too young. At the moment I am having trouble connecting to the servers so that is a whole different situation, I don't know if you will have the same problem but that should fix the age restriction.
I hope I could help and if I didn't I'm sorry but that is all I know.
