Welcome to scubaboard! I'm from Largo (outside of Tampa) aka Sun Coast. You live in a great spot for diving. I often trek across the state to go diving in your neck of the woods.
You're probably already well aware, but Blue Heron Bridge is a great site in your area. It's free to dive (and park). There's also plenty of good diving in the Atlantic near you. No shortage of dive operators to take you out for drift diving. If you do go there, get there early. Parking can fill up fast.. at least the good spots nearest to the dive do.
The keys aren't bad but they're not THAT much better than what you've got right on your doorstep! If you haven't done Blue Heron Bridge, that should be your next dive. Info here:
Dive Blue Heron Bridge - Phil Foster Park Pura Vida Divers : Discover South Florida SCUBA Diving I've heard it described as one of the best dive sites in the US. So far in my limited experience, I can't disagree. People have seen manatees and I've seen dolphins/sharks/rays/sea stars. There's lots of small critters like nudibranchs and octopuses. All sorts of small "aquarium" type fish too.
If you have your gear (including a full tank) you just drive over to Phil Foster Park, get out of the car and go diving. There is no fee to enter the park, no parking fee, and no fee to use the water. You do need to dive during slack tide in order to ensure good vis and low current. BHB is in the process of becoming a protected wildlife preserve as well. That link to Pura Vida that I gave you will tell you all you need to know.
If you haven't already got a favorite local shop, I've had good experiences with several over there:
Jupiter Dive Center
Force-E
Narcosis
Pura Vida
Blue Heron Bridge Scuba/Little Deeper Charters (their shop was empty but they ran a decent boat operation right at the bridge).
I usually pick Force-E if I need nitrox fills near the bridge.