Changing Apple ID

Make a backup of the phone in iTunes.

Back up your iPhone, iPad, and iPod touch

Backup - Restore your device from an iCloud or iTunes backup

Another approach is to just change the ID on the phone. There may be some data loss, but you can minimize it. If syncing photos with iCloud, ensure Optimization is turned off in Settings/Your Name/iCloud/Photos and/or in Photos/Preferences/iCloud. Then make sure full resolution photos are on the device/computer. When signing out of iCloud, if asked whether you want to retain data, choose yes. Messages conversations will be lost if they are addressed to the ID. See the article below for other places that the old ID should be removed. Also ask your Family to set up Family Sharing to keep access to your apps/purchases. Also see Winston Churchill's response in the below discussion

Apple ID – Create

How to transfer all files from one iCloud account to another

 Apple ID email address or password - What to do after you change

Family Sharing

Family Sharing - Set up

Family Sharing - Use your own Apple ID for Family Sharing

Family Sharing -What types of content can I share?

Family Sharing - If you don‘t see your family‘s shared content

Family Sharing - purchases and payments

Family Sharing - Hide and unhide music, movies, TV shows, audiobooks, and books

Family Sharing – share iCloud Storage

Family Sharing - Share an iCloud storage plan with your family

Family Sharing and location

If you start a completely new Apple ID you will have to download all our data from the old one and then upload it to the new one once signed in. However you will not be able to transfer any purchases music, movies or apps, though you cojuld get your family to set up Family Sharing and join that.

Family Sharing - Apple