My DS is 2.5 and we just went. Luckily, he doesn't have tantrums often - but he's still a 2 year old and they happen.
What we did was:
1. Try to prevent.
I kept snacks on me, I brought a couple of his favorite cars, I had glow sticks from Target, we kept hydrated (literally, after every ride, every bathroom break, every few steps, I was pushing COLD water down him. I had a good thermos that I filled from water bottles we froze and that helped a lot).
We made sure he got his nap. He napped in the stroller. DH and I used that time to sit in the shade or if I wanted to go shop, I would shop while he slept. We very rarely went into a shop when he was awake.
2. Nip them in the bud.
If I saw he was starting to blow, we'd change tack, try to distract, give him the option to make some decisions. We'd take a break. We also had a rule, no ride was worth more than 20 minute wait time. We were AMAZING with our FP+. By the way, trick we used, we only went on rides he liked since we've been before and this trip was about him. So DH would take him on a ride while I sat out. After the ride, I'd take him using my FP+. This works for a 2 year old since they aren't part of the FP+ system. Once he's 3, we're stuck.
3. When it happened - the worst was the very first night. We had driven for hours, we were supposed to meet my sister and her husband at Raglan Road at 5:30 for dinner. We were hungry. It was hot and we had left my DS' stroller in the car because we hadn't realized HOW FAR we had to walk from where we parked at Cirque to Raglan Road. UGH. (Ended up carrying him back - not fun) None of us were happy. My sister and her husband were more than an hour late because they got caught at work. DS was REALLY not happy. When we got seated, they gave us a GREAT table right next to the dancers. Great, except, the sound started getting to DS. He got upset and was "performing" for his aunt and uncle and everyone else and actually smacked me and started yelling/tantrum.
What I did - I calmly picked him up and carried him out. I didn't say anything to him. He was upset because he was no longer in the excitement and wanted to walk and cried more, but he needed to be carried and removed from the restaurant as quickly as possible at that time. I took him outside, and talked to him about how we don't hit. Set him down on the ground for a minute in timeout until he calmed down a bit and was just crying a little. Then after it was done, hugged him and talked about why he got timeout again (now that he was calm enough to understand). Had him repeat back to me why he got timeout. One more hug, then started distracting him with talking about the menu, the statue, anything. He calmed down completely within a few minutes and was quite happy the rest of the time after we got back in and got to eat. This is usually how our pattern for tantrums works. We always make sure we end a timeout with hugs and kisses though and doing something happy - even if it's just talking about how pretty the sky is.
We also have talked (trained?) to our DS and make him understand that he'll often get what he wants if he can ask for it nicely. Drives me and DH nuts when he whines. So we've gotten pretty good at saying something like "Can you ask for that nicely?" If he'll say "Can I have X, please, Momma?" (usually in this sweet voice he does when he is being "nice" I'll respond "You asked for that so nicely!" and then give it to him. Usually it's something like getting to play with his iPad when we're sitting around (something I'd be fine with him doing anyway). If it's something he asks for nicely but he can't have, I'll tell him no, but that I'm so proud of how nicely he asked - then will try to find something else as a mini-reward for the being nice part , even if it's just hugs/kisses.