I believe your question is, what do I fill a raised bed with?

You're correct that 100% compost is not the best way to go. There are several reasons for that. What you need is simply a mixture of topsoil and compost. Depending on how much you need, you can either buy bags of topsoil or get a load delivered or if you have access to a pickup truck, get it from a nursery or soil supplier. They may even have a 'garden mix' which might save you the amending.

Just make sure of a few things. You want a soil that is balanced in terms of sand/silt/clay if possible (loam) although you may not find that in Florida. Ask where they got it to make sure it's not full of noxious weeds. If you're buying bags, don't get potting or container mix, and keep in mind a lot of the 'garden soil' products are pretty much all organic too. Poke a hole or find a broken bag to see what it looks like. You need mineral soil for at least half the volume.

If you're buying bags of compost, it's good to get several types and blend them. Watch for too much soil - I've seen compost bags that had more soil than the 'topsoil' bags next to them which looked more like compost. Buyer beware. You kinda get what you pay for with store bought compost: the cheapest has the least organic matter and nutrients, but the most expensive isn't necessarily better than the middle ground.

Be prepared for the beds to settle and compact and require some topping off next season.

"Myth #1: Topsoil means that it is going to be good, dark and rich soil.

Balloon popper: There is no legal definition of the word topsoil. Technically, it is whatever is on the top. Sight unseen, you could order 5 yards of anything from beach sand to adobe brick material. Always go to look at what you are buying if you are unfamiliar with the soil seller to know what you are purchasing."

From this article. http://msue.anr.msu.edu/news/the_shocking_truth_about_topsoil

What is needed is a good soil mix and something called "topsoil" may not be that.

Soil is composed of the mineral portion (the sand, silt, clay) organic matter, air and water. Some few are lucky enough to have loam, a soil type generally recognized as the best soil for growing things. https://hort.purdue.edu/ext/loam.html

Most of us have sand or clay and amend that with ample amounts of organic material to get a soil that will grow plants without too many problems.

kimmq is kimmsr

I'm not a believer in buying soil.

Improve what you have by adding compost, or, adding veggie scraps directly as described by... when can I stop digging?Posted by Garyoldman Parsons.

The trouble with buying in soil is that you don't get as good a result as you would if you do the hard yards yourself. Plus, there are other problems created when depositing one soil on top of another.

Aaaaaand, as kimmq said, buyer beware. There is such a lot of rubbish out there. I am yet to see something that I would want to actually purchase. Oh... that's right. I foolishly let go a huge, old pile of composted horse manure because my brain could not compute that what I was seeing was so lovely. I had expected not to be impressed and when I went and looked at this heap, and saw that it looked like soil, I could simply not compute it. A few months went by (yes, months) and I realised that what I wanted was as much of that heap that I could get. But too late. It was GAWN! I could not believe that I had been so stupid.

These sorts of heaps do not come around very often, sad to say.

I don't disagree with you guys on the subject of improving the soil we have (as you know), but seeing that the OP had already set up a type of raised beds and wanted to fill them, I thought it best to just give advice on how to do that.