How can I tell if this is a valid Ghana passport number

Most likely it is a real passport, all the scam people, use real ones, and photo shop photos, some jjust pay someone to use theirs, others even hire the person to do some video work.

In Ghana, if this is a dating scam, normally there is a large office of people, working three shifts a day. The person you "chat" with today, may be a 60 year old grandma, and tomorrow a 23 year old college student. They read past conversations and use pre approved scripts to tell you.

If you go for video, they have special girls hired to do the video chats but normally have excuses why they can not video.

Normally they will ask for about 3 or 4 times the correct amount of money for visa and items, then find reasons for more and more money.

So tell us your story.

In short, if you have to ask, then you have doubts....believe your doubts. You are likely being scammed.