How to ween family member from using my Apple ID on their iPhone

Change all of your passwords and passcodes, as those are best assumed to be compromised.

If you think your Apple Account has been compromised - Apple Support

Then unlock the device.

What to do before you sell, give away, or trade in your iPhone or iPad - Apple Support

That solves your data compromise and ownership issues and most of the other risks.

If you want to provide some continuity of data access, provide these links:

• How to “unshare” an Apple ID - Apple Community
• Archive or make copies of the information you store in iCloud - Apple Support

For apps and other content not associated with the available Apple Account, either enable Family Sharing and share that, or delete and re-download the apps or content.

Alfredo Jahn wrote:

I didn't mention anything about my account being compromised... But thanks for the other links. I'll take a look. Thanks

Depending on the setup details, and depending in how the apps got onto the iPhone under your Apple Account, all of your passwords are quite possibly being shared.

if the credentials are known, your Apple Account can also be permanently disabled, and devices reset or bricked, among other details. So if you want entirely clear of sharing, treat it as a compromise, and start changing passwords.

If this is Family Sharing and they don’t know your credentials, amd want clear of Family Sharing, then they can re-download apps from their own Apple Account.