Going back to Florida for 3 weeks next month and think we're going to take a trip to Wekiva Springs whilst we're there, heard great stuff about it.
Couple of questions though
1. Do I need to book in advance to be able to canoe, if so how far in advance?
2. I've never actually done canoeing before, will that be a problem?
3. Are there any nice walks we could do there?
Just ran into this but I imagine it's not too late. I have been there many times, most recently in the spring. Depending on when you go, it is generally best to go early in the morning. It's not one of those things that is anticipated to be super packed, but we have learned that going on a weekend late morning early afternoon has been problematic. Especially if the forecast calls for favorable conditions. I say get there early and beat the possible crowds. I have seen them close both entrances to capacity (both the park itself and the island where mostly young adults/adults go to drink).
Canoeing is fun and there is no problem doing it. You rent the canoe/kayak and off you go (it's like 12.50 per person or per boat, I don't remember.) Make sure the people you go with understand there is gonna be some strength needed and the possibility that someone may have to jump out and push the canoe around or out of some sticky situations. I've seen kids get stuck in mangroves and cannot maneuver themselves out. Except for the initial area where you rent the boats, for the most park the waters are extremely shallow and clean. I went with my girlfriend and if it was just her or one of her friends, they'd be S.O.L.

They pretty much give you a whistle and say "Have fun". You can go pretty far and even up to another park if you so wish. Keep in mind that is about 8 miles north. I also know you can go to Rock Springs and horseback ride back to Wekiva.
I've never walked around there, but there are nature trails. Typically we are too lazy to do that after the canoeing. They look nice, however. There is certainly wildlife out there. You will see otters, alligators (small ones), lots of birds and fish. Don't worry about the alligators, they are scared of the canoes and I have never seen one that would even pose a threat let alone bite you. They're mostly babies. Keep in mind though that this is Florida and you can find gators in any body of water, even a puddle. There has been an increase in bear sightings in that general area. However, they seem to avoid the springs/streams/ etc and stick to the inland parts.