If it’s your first time, you are going to have a blast. I went in August. I would suggest to do the Hilma Hooker at dawn if you can. Others are 1000 steps (actually like 68), Alice in Wonderland, Salt Pier, Oil Slick Leap. If you’ve already been there, have fun at the sites you are already aware of!
Also when I was there in August, my buddy and I found an Octopus that lives near the dock of Captain Don’s habitat. Right when you jump in, there is a rope line with a cement anchor. Right around there is an Octopus, we could find it anytime because it was being followed by three or four fish.
Have a great time.