Have you ever drank before? If you have any idea what you likle heading into it, go that direction, just go with the highest quality you can afford for the occasion. I'm getting old now (getting reallllllly close to 40 ) and don't like to tear it back anymore, so I too would suggest keeping it around 4 drinks, no matter what you choose for the tasting. The trip is part of the destination, but if you get there and it's closed (or feeling like a pile of meat that something beat to a pulp and then peed all over) it ain't worth it for me. YMMV Happy bday sir!
I'd suggest Coors Light as a first beer, then when he actually has a good Belgian beer he'll appreciate it more.
Assuming that - having used Coors Light as his "gateway" beer - he ever has any desire to taste beer again.
Happy b-day Justin! So many choices... Being from Kentucky, I'd go with a bourbon. Probably Maker's Mark.