How to make sure no passwords/accounts on used Mac?

[Shintsu]

I am going to be looking at used MacBook Pro, but I want to make sure it doesn't have any passwords or accounts on it that would leave me hosed without the original owner. What all do I need to check to ensure I am fully the owner on it and the previous owner doesn't have any passwords locking something out that I won't be able to bypass? There's one that's particularly ominous IIRC that's a firmware password or something? Also, do MacBooks have the ability to be in iCloud where they can be locked out like an iOS device can?

 

[ApfelKuchen]

This Apple support article holds some answers for you: https://support.apple.com/HT204455

First thing to do is turn the Mac on.

If the previous owner did an erase/reinstall as Apple recommends, the Mac will startup in setup mode, as if it was a new Mac. That would be an excellent sign that there are no other User accounts. (If the previous owner did not do this, you should do an erase/reinstall per this article https://support.apple.com/HT204904 to be sure the Mac is clean.)

Firmware password can be tested for by trying to boot the Mac to Recovery - (Command + R at startup - https://support.apple.com/HT201314).

Yes, MacOS has Find My Mac, which is very similar to Find My iPhone. If you put the Mac in Lost Mode, it adds a firmware passcode to the Mac (that article on firmware passcodes includes info on this).

 

[Weaselboy]

Also, do MacBooks have the ability to be in iCloud where they can be locked out like an iOS device can?

Yes, there is an iCloud feature called Find my Mac that can remotely lock a Mac. First thing you do when you take possession is reset the NVRAM to clear that out so the old owner cannot remotely lock it.

https://support.apple.com/en-us/HT204063