FaceTime and iMessage user content history?

I allowed my Mac to be taken out of my possession for service - it was taken to a backroom twice, for quite some time, so that a more senior technical person could be consulted about it. Later I received emails welcoming me to iCloud and two emails acknowledging my sign-in to FaceTime and iMessage. I am not normally an iCloud user, nor would I ever carelessly or thoughtlessly join FaceTime or iMessage. So I'm fairly certain that my machine [identity] was hijacked for a short time. I have since changed my AppleID password and some other security controls. However I have no idea of what has been done using my identity and my AppleID. Is there a user log or history that a moderator or support person can look at to see what happened for a specific AppleID over the last couple of days? I don't want to sign-up to these services just to find out what has happened. About a day later I did go into iCloud to see if 2FA was switched on and found many iCloud services that were enabled so I don't know what has happened in my name. I suspect just disabling my iCloud access to these services does not disable the respective sign-ins. Does anyone know how I can find out what has occurred?