Since you said canoe I suggest you look into this group.
You can search the trips past and present and tell where to paddle. These paddlers maintain a rather relaxed pace. They have a facility in the Ortega Farms area of Jacksonville. There are some real paddlers there…and some that like the social aspects better. But the trips are real.
Kayaking is done with the Seminole Canoe and Kayak club but kayaking is the main purpose of this club hence it is named, Florida Sea Kayak Association. They largely are 14 ft and longer and maintain a 3 to 3.5 average for a trip. You might want to use the trip lists for locations and suggestions. We focus on safety at least once a year with some self rescues sessions.
You might want to take lessons for you or the family. It is a lot easier to train in controlled atmosphere than when the wind is blowing, the boats are waking by, the waves are breaking and it is raining.
The camera … I keep mine on a lanyard in a pocket on my pfd. That way I can pull it out quickly. Or drop it to paddle or handle some thing and it doesn’t sink away. Waterproof does not always float or float near by.
The gps watch will keep track fine. Exceptt they often track by how much time per mile instead of MPH. Which can be interesting when you want to figure out how long it will take to get to the end of the paddle. I use a Garmin 78c . One of the FSKA guys can tell you how to get pretty maps out of it.
We often use Google Maps to plan trips, locate boat ramps, and measure distances. Use it wisely and look at the map and at the sattiletie (sp?) (photo)
October through April are the best months for paddling in NE Florida. I know it is backwards. But summer is just too hot. Think early in summer. You want to be on the water by 0830 and off by noon. The jet skis, ski boats and boat riders will be out at 10am. Stay away from Fort George Island sand bar noon to five. Especially after 3pm. Too much traffic and impatience.
Look at the Four Creeks area. See FSKA trips for Four Creeks.
Kayak Amelia at Big Talbot island…aka Long Island… is a good facility and outfitter. YOu can , allowing for tides, kayak/canoe either out to the marsh or out to the Nassau sound. They have rentals. They have launch fees, was $1. They also have good information. They used to arrange for lessons.
Do not under estimate paddles to Cumberland island. It can be difficult. Tides are aggressive. Weather changes. It is not for beginners. One of our Cumberland island paddles last year included a water spout.
Look into St Mary’s river Scotts landing at Hwy 1 up about five miles or so and return. Mild current and pictures. There is a park for turning around 5 or 6 miles up.
You might find some information here… https://floridadep.gov/PaddlingTrails
Okefenokee… get the family a little experienced before going up there. Sometimes you don’t see a single gator. Some times you don’t see a single gator…cause they come in groups of five. Stephen Foster State Park, at Fargo, is the western gate to the swamp. Several good trails there. Don’t take dogs. The “canal” at Folkston is the main eastern entrance. Nice trails. Canoe rentals both places. Has a museum like display. Both places have entrance fees…and ice cream.
Mayport…tides can be moving 8 mph there. Don’t take the family there.