Help setting up second controller

You'll want to look at the Family & Online Safety section of the Microsoft help center:

https://beta.support.xbox.com/help/family-online-safety/browse

Basically, you'll have to create a second account, so you and your son both have your own account, and then you set up a Family on your account and add your son to the family.

When you are signed into the Xbox on one controller, you can sign into the second account from the second controller by pressing the Xbox Guide button on the controller to bring up the sidebar. On the accounts tab you can choose to sign in as a guest to
your account or as the second account that you create.

You should clarify what you mean by "activate a new person".

Hi there

If you would like to enable a 'Quick Sign-In' with your controller when the Xbox is booted up, please go to Settings>Account>Sign-In, Security & Passkey. You will then be able to choose the controller and account that signs in when you next turn your console
on.

Hope this helps!

If you would like to set the controller to log into a specific gamertag when it's turned on then please go to Settings>Account>Sign-In, Security & Passkey. At the bottom of the screen you should see a This controller signs in. Click it and you'll be
able to select to link it to a specific signed in gamertag.

Not sure if this will help but try going into the minecraft control settings on the second player and turning the sensitivities up because it turns itself to 0 for some reason.