Florida beaches in February

No specific recommendations, but go to uscampgrounds.info, enter a city, state in the search box, and you can see all the publicly owned campgrounds in the area. In many parts of Florida there are lots of city and national forest campgrounds. They won't be fancy but many of them have water & electric sites, plus a dump station. There are links to the website for each one on that site. Very very useful.

Read the basic info, after that, Google, RVParkreviews, and Trip Advisor are your friends.