Good info above. Take a look at this article and its photo.
Check out the How do I know if my computer has USB 3.0 ports? page at Sweetwater — the world's leading music technology and instrument retailer!
www.sweetwater.com
On the 2.0 vs 3.0 question, you can tell by looking closely into the socket. A USB2.0 socket has only four contacts as flat strips that come right to the front edge - see second item from the left in that photo. A USB3.0 socket has those same four contacts across the front, PLUS behind them FIVE small contacts. In the photos, you can see them as slightly raised behind the front ones.
Distinguishing between varieties of USB3 Type A sockets is tougher. One good clue to help is the suggestion in the article to check in Device Manager the details of what types of USB ports your...