Congratulations! There have been lots of changes just in the past few years!
I'm not sure if you're a ride enthusiast, but I hear Kraken is the first thing to do before the lines get long (this opened after my last visit). Next is Atlantis, which I did do, and IMHO, I think this is an excellent ride!
Other than that, the rest of the day can probably be planned around the shows. Be sure you get a map when you enter, which will list all the shows. Choose which ones interest you (or if you're like me, ALL of them), and plan accordingly. I like to put a little check mark next to the time of the shows so I know where we're going when. I also enjoy feeding the sea lions, I think it's $1 for a plate of 3 fish. But BEWARE OF THE SEAGULLS!!! They steal fish, and they will ruffle YOUR feathers a bit!!!