Be careful if you venture up into north lagoon, under the bridge from treasure island. Stick to the channel markers there are a lot of shallow areas. Watch for the no wake zones. Some nice houses to check out on the water up in there.
Head for the best spot on the island. There are 2 docks, (you won't use them, just anchor around them) it's a huge area of clear shallow beachy bottom. Maybe 3 miles from the pass on the back (bay) side of the island. We would back in and anchor up about 40 ft from shore depending on the tide. great place for hermit crabs and sand dollars. and it's just a short walk over to the gulf side. Shells a plenty and beautiful open white sand areas. Watch for turtle areas though.
When exploring on land, Go down north lagoon and look for Mr Surfs shop on the inland side of the street. There is a trailer next to it with outdoor seating. It's called Finns. Awesome food. Great locals place.
Also, just south of treasure island on north lagoon when you make the turn to the left toward the state park, there is a great local bar called Patches just after the turn on your right. Awesome food and a decent beer selection.
Want a great date night spot on the water,
http://uncleerniesbayfrontgrill.com/ . You can pull your boat up or go by land. It's up in the bay on the panama city side. If it's nice out, the upstairs open patio/bar is awesome. Great food, a little pricey.