How do I disconnect two iPhones?

It would sound like the two of you are sharing the same Apple ID. If that is the case, one of you needs to get your own Apple ID, so you do not share text messages. In the meantime, go to Settings>Messages>Send & Receive, and remove the checkmark from everything except your phone, and have your Dad do the same thing on his phone and remove your phone number.

Hi

This is because you are sharing the same apple I'd

All apple devices with the same apple I'd will get the same information.

Everyone need own apple I'd they are not made to share.

Change one I'd.

Cheers

Brian 🇬-1F1E7;