Hi Izzy, Welcome to Key Largo.
There are more operators in Key Largo than gas stations, most are very good at accommodating new divers as most of the diving is shallow, clear, beautiful reefs and wrecks. Lots of great info in this thread
http://www.scubaboard.com/forums/florida-conch-divers/362149-florida-keys-guide.html. If you start searching the FL Conchs forum, you will find that Key Largo is an often discussed topic with info specifically about dive sites, training, dive ops (many participate on Scubaboard, so don't hesitate to contact them), conditions, temps, eateries, etc. There is something for everyone in the Keys. Don't hesitate to call various dive ops and chat about what they have to offer, and get a feel if they are right for you.
If I can answer any questions for you, please don't hesitate to PM or call. Whether you dive with me, or one of the many fine ops here in Key Largo (I have friends working at many), we all want you to have a great experience.
While you are in Key Largo, please stop by and say hi :wavey:.