I want all these devices off my phone

Tap on Settings. Tap on your name. You will see a list of all devices that share your Apple ID. If you see any that you don’t recognize, tap on each and delete it. Then change your Apple ID password so anyone sharing your Apple ID won’t be able to share it again.

Go to Find My app, or you can log into icloud.com and make sure the other devices are removed from your account.