Solo senior first Florida roadtrip looking for 1 or 2 nights in various locations. Just want to walk the beach, stay fairly reasonable hotel or air BNB(-150 ish) on the beach-walk to casual restaurants -first of March 2020..Arrive Jacksonville ?..Research so far that looked like it would work :
Fernandina Beach
Atlantic Beach
Velano Beach
Flager Beach
Boca Grande
Sanibel Island
Ana Maria Island
Would like to get the list down to maybe 5 locations... Would be appreciative of any advice/suggestions.. Just go down and wing it or have reservations and itinerary all worked out in advance? Thank you in advance for your time and thoughts...

Pass A Grille
St George island
Seaside
Navarre Beach
Santa Rosa Beach

Look at other places to fly into that might fit with your trip route, like Orlando, Tampa, etc.

Do you plan a road trip to all those places or are you planning on staying in one of them?

Thank you for your response. Im looking to whittle the list down to about 5 cites and stay in each 2 nights.. I dont care about real hot swimmable weather.. I thought Northern Florida would be more off season 1st of March-Thought the flights to Jacksonville may be cheaper as well as picking up rental car. Thank you again

You should decide Gulf Coast or Atlantic Coast, not both. Love Pass A Grille, nearby St. Pete has great culture and lots of see, Sanibel Is and Siesta Key would get my vote, with visit to Sarasota (Long Boat Key $$$$)

Here's a second vote for St. Pete. It has all anyone could ask for, pelicans, museums, breweries. You can fly into Tampa.

For less expensive flights look at Jet Blue and Southwest. Go to their sites, not the consolidators. Southwest has a "low fare calendar" which will give you the lowest fare between two places for every day of the month.

JAX, DAB or MCO have cheap flights often. We like Jet Blue. Allegiant fly into Sanford Orlando. New Smyrna Beach is very nice. Great little Hampton inn and new hotel on the ocean. Nice places to eat. I love Amelia Island and Flagler.

We really need to know where you are flying in FROM. You might want to include Ft. Myers/Naples IF you are using Southwest and IF you want to include Sanibel.