My wife from usa is coming to me in ghana thoes she need to take shots.and if she has to take shots how many needles she have to take,, and why at all she need to take the shots?

There are no shots required to travel to Ghana.

Are you sure this is your wife ? Something does not sound right ? You seem to know nothing about this, and your wife is a US citizen merely gets her passport and a visa and travels there.
There are no other requirements.