I met a guy on a dating web site, he says his name is Joshua Antwi DOB 4/04/1970, He lives in Ghana and wants to visit me, so he sent a copy of his passport, I need to know if it's legitimate

It may well be a legitimate passport, but then there may be 40 people using that same passport. So let him come, AHHHH I bet he wants you to send him money??

It is a fraud of course, but if you don't want to believe me, go to the US embassy web site for Ghana and read all the warnings.

Next if you just have to send money for a plane ticket you can do it direct to the air line, make it a pre paid ticket that they can not exchange for cash.

I bet they try and tell you that you can't do that

Or they will be robbed on the way to the airport, or lose their passport, or have to bribe some official.

Have they sent you a copy of a VISA to come to the US

A agree with Fr Chuck, smells like a popular scam.

Joshua Antwi is the name of a known scammer in Ghana!
If he is asking for money etc it is probably the same criminal lowlife