Can you go just for the day to walk trails and price for day entry

Yes you can

Yes and its a beautiful place for hiking/walking. I believe it is about $5.00 per car

4.99 for a car full of 8 And cheaper as there are less people or walkinf or biking

All Florida and Federal parks have day entry. You pay by the car or bicycle (if on bikes) to enter.

Yes you can, I believe it is $5 per car for entry fee.