Look at Tradewinds at St Pete Beach or any surrounding resorts. We stay at a small boutique hotel (Postcard Inn) a few hotels down all the time and my teens enjoy it. Lots of beach to explore and just across from hotel is 7-11, dunkin donuts, chick-fil-a, ice cream shops, waffle house, Publix, beach stores, etc. Use google maps to explore what is around these resorts. It’s also a short drive to Johns Pass.
Alden Suites is popular and near Tradewinds where the kids can walk to Tradewinds and pay for the water island, jet skis, etc.
Not walkable Tradewinds (because it’s in Clearwater, FL) but worth mentioning... very nice and popular is Sheraton Sand Key Resort. It’s a little more out of the way.