How can I extend my driveway?

Not knowing your particulars, I would suggest looking into chert.

You can use asphalt, pavers, patio stones. Still would need to dig down into the ground. A solid base of fine gravel or sand. Then lay the mew material.

We used paver base under cement caps (8x2x16) laid sideways in a line where we expected the tires to go, encased in bricks. All of it had to be locked in around the edges, so we dug a trench around it for cinderblock first (once we knew how the bricks would lay), that we later anchored to the ground with rebar drove into the ground in the two holes, then filled the holes with concrete. We had to consider water drainage so left gaps for that, and added a walkway anteriorly so we could roll the trash can across instead of walking around the whole thing. Also built up the outer sides of the cinderblock so it wouldn't be a big step down or major trip hazard. Filled in the gaps with dry cement and brick fragments. It wasn't our choice to do it this way, it was a budget and easement issue. If we knew what we were doing we could have ordered construction base and had it dumped, instead of the truck delivery with the pallets from the hardware store like everything else. We spent $400 in bricks, probably $300 in paver base, another $400 or so in concrete blocks to make a 2-car driveway plus 16x4 walkway, over the course of a month or more, with 4 people. Plus expenses I don't remember of course. Time consuming and back breaking, major body-mechanics alert, like a lifting workout at the gym! If you want to cover part of it, like we did with a single carport for about $1000, do the carport first, then work around that.

Since you are in St. Pete, FL, how about using crushed shells?