How do I locate a stolen MacBook without Find My Device enabled?

The only way to find it would be the old fashioned way, by looking for it. You might be lucky enough to find it in a pawn shop, thrift store, possibly someone trying to offload it on Craigslist, FaceBook, etc.

By now one would think a stolen Mac has no value. Without its login credentials a lost or stolen Mac is quite useless. Even if your father disabled the requirement for a login password the best someone could do is erase it, but even then attempting to install macOS results in a dead end: still a brick.

Criminals are like anyone else; there are smart criminals and others that are not so smart. Anyone stealing a Mac is not quite ready to join an Ocean's Eleven crew. That Mac is certain to show up somewhere... eventually.

Be sure to ask your father to follow the three numbered steps under "If you can't find your Mac or didn't set up Find My" in If your Mac is lost or stolen - Apple Support.

If your Mac is lost or stolen - Apple Support

"Find My Mac is the only Apple service that can help track or locate a lost Mac."

John Galt wrote:

Criminals are like anyone else; there are smart criminals and others that are not so smart.

Like the bank robber who wrote his demands on the back of one of his own personalized deposit slips.

The story didn't say what happened to him, but I imagine that it was not too long before he was enjoying an extended "vacation" at "Club Fed."