Well, if you do a shore dive, way less gear is needed. You'd want to keep the minimum.
Boat diving is way more gear. You can rent the tanks, if you want to simplify. However, I do the reverse and dive my own 130HP. Yes, 1st floor is more convenient. Some apartments come with small storage spaces (cells size of a porty potty), located on the first floor, you can keep tanks there. Having an SUV is convenient too. Usually you'd bring your car to the entrance and have a few trips to your condo to bring gear down. A hand truck or a dolly can be helpful on long runs (some hoa might not like the potential of wheels tracking in dirt). If you can afford, you can rent a small storage space elsewhere, just for gear.
You also have to figure out how to wash the gear after the dive. Most marinas offer a hose, I stay after most leave and hug the hose time (after a boat dive). Some condos have a common car washing "port" where you can hose your gear down, also you can do it on your balcony if hoa is cool with it (again, 1st floor helps). After a shore dive most places have a beach shower, I usually hose off salt water, then in depth cleaning at home.
PM me about Ft. Ltd condo living, I got two (edit: no rent).