I need my old phone disconnected from this number

I just got a new iPhone 11 I traded in my iPhone XR and got this one , both of them have the same number my old one still has the same number as my new one which is the iPhone 11 but all my messages is going to my iPhone XR and I need them to be coming to my iPhone 11 because this is the phone that I’m using right now and I can’t log into any of my gmails or anything because of this so how would I disconnect my old phone from this number so my messages would only be sent to this phone and not my old one