When it comes to land, a one county area is probably too small unless you have a niche and know it well.
Pat Porter, who has a pretty good Amazon book on land flipping suggests that setting your personal geography is one of the most important steps in the process of setting up a land investment business. I think a 3-5 county area is more realistic. Personally, I also have investment targets outside my state.
In land investing you need to have a clear vision for the type of land you want to invest in. Are you looking to flip small residential lots, large rural parcels, landlocked properties where you establish an easement, commercial land, etc. etc. Once you have established this, then you can begin to think about sourcing and your budget.
Florida is a tax lien state, so in my opinion, that will probably be one of your best ways to get started. Try investing in some liens on land that fits your criteria and if you are lucky, some may mature. Otherwise you need to do some marketing and connect with folks to find land deals that aren't already at or above market value unless you plan to develop the land. You will also need to learn (if you don't already) about zoning regulations and restrictive covenants in your area. These can make or break a land deal. Many properties also have restrictions because they contain wetlands or environmentally vulnerable habitat, which is a particular problem in Florida. Some land may also be contaminated, so be wary unless you want to pay for costly environmental site assessments. Lastly, keep in mind that getting title insurance on land can be surprisingly more complicated then you may expect and not every parcel of land is sold with a 100% interest stake.
The problem with Sarasota County in my mind is that it is a high population area with limited tracts of undeveloped non-wetland property. Your best bet as a land flipper would probably be to flip residential or commercial lots, but the competition is sure to be far more fierce then if you were operating in another part of the state. If you want to follow traditional land flipping strategies which aim at rural parcels of 20+ acres, then some of your neighboring counties like DeSoto County or Hardee County may yield better prospects. Again, tax lien investing could be a quick way to get your feet wet (no pun intended) in land investing in Florida.