How to change back to my Apple ID for updates in App Store
What ever was downloaded under your Dads Apple ID stays his.

Any app download under his Apple ID will continue updates under his Apple ID. You can not change that.

Sign out of your Dads Apple ID.

In order to change that and have your apps, you need to use your Apple ID and re-download stuff to be yours from now on, including updates to your apple id.

Applications from appstore are Apple ID associated.

Simply stated: Delete all apps that were downloaded under your Dads Apple id and download them again under your ID.