Mary Lynn, being that you are a newly certified OW diver with 7 dives, coming in from Georgia, have you investigated the springs and sinkholes of North Central FL at all? You realize that there is nothing cheap about diving them when one does not own any gear aside from a mask and snorkel, right?
Plus, being that you’ll need to rent an entire gear package from a dive shop or dive site, you’ll then need to leave a credit card as security when leaving with their gear to dive elsewhere.
This sport is costly, and that’s all there is to it. No diver ever has enough gear, or no need to update or upgrade their stuff, and then there are maintenance fees for the gear as well.
Plus, for you to gain the 20 dive minimum, meaning 13 more, you’ll need to do 2 dives a day (which would be typical) for 7 days, unless out on a boat, and doing 4 in one day for Advanced Certification, and that too is costly.
Not to dash your hopes, but I have a very experienced dive buddy working as a volunteer at the Shedd Aquarium in Chicago, who says that there are constantly so many divers volunteering to get in at the aquariums, and very few make the cut. Without some major connections and specialties under your belt, the chances of getting in as a diver, are slim. You may get in to feed at the Georgia Aquarium, maybe...but you wouldn’t need 20 dives for that to the best of my knowledge.