How to disconnect my iPhone from macOS?

Hi ReelJannaLive,

Thanks for using Apple Support Communities. We might need a bit more information in order to fully answer your question. Perhaps you mean that you no longer want to sync Apple ID information between your iPhone and Mac. If so, disabling iCloud features on your Mac will help. The following is from Change which apps sync and store data with iCloud - Apple Support.

"On your Mac

1. Choose Apple menu  > System Settings or choose Apple menu  > System Preferences, then click Apple ID.
2. Click iCloud.
3. Select or deselect each app. If you don't see an app, tap Show All to see the full list."

If you're referring to something else, please provide a bit more detail about what it is you'd like to do.

All the best.