Georgetown airport is a small, friendly and relatively efficient tourist airport. The one drawback is the size of the waiting area which can be standing room only if a couple of jets are leaving at the same time.
Once you check your bags in, a good alternative is to wait at Kermit's airport lounge across the street, which offers free WiFi and sometimes a Rake and Scrape band. They sell cold drinks and take-out sandwiches that will surely be better than anything available on your plane. Just remember you can't take liquids through security.
There are a couple of very small gift shops once you pass through security. There is also free wifi in the lounge area, but it can be slow depending on how many people are hooked up.