Professional Friends vs. Real Friends
Ghanaians are typically kind and welcoming. Indeed, Ghana has a reputation for being one of Africa's friendliest countries, and many recommend it as a great starting point for first-time visitors to the continent. Ghanaians would want to show you around town and teach you basic skills such as shopping. They will also teach you words and phrases in Twi, the most widespread of Ghana's nine or so languages.
However, there are those people who do not communicate with outsiders with the best intentions. They're known around town as "professional pals." These people will want to befriend you fast in order to gain access to your money or things, not because they actually like you (though you're probably fantastic). This phenomenon is not specific to Ghana; as with anything, common sense is required.
Note! Don't tell complete strangers where you're living too soon after meeting them, and don't go anywhere with somebody you've just met without notifying anybody.