Good advice sotto.

I didn't see any mention of sunscreen. Carry some.

A hat is vital. I would pick a hat with all-round wide brim instead of a baseball cap that leaves the ears exposed but that's just how I roll.

Walking shoes and comfortable clothing are vital.

These sorts of places are more enjoyable if you aren't loaded down with a huge amount of stuff. Look around, or ask, about storage lockers. These are usually set up near a central area, often with bathrooms and other amenities, and can become a staging area for families. This applies even more for people with kids. Having several sizes of bags at hand allows you to stuff the big one in the locker and take a butt pack or tiny duffel, with minimum supplies of the most vital gear, mostly bottled water and snacks, with you.

If you get there when it first opens observe any looping rings of attractions and which way the crowd is breaking. Most people seem to favor turning right and going around the loops counter-clockwise. If they mostly go one way; you go the other. The advantage is that you avoid the crowds and have rides and attractions to yourself for a few hours.

While you are planning a visit call the 'visitor services', or whatever they call it, office. They can give you little gems like what days and day/s of the week see the fewest people. The difference between a day when there is no waiting for a ride and one where you wait an hour is substantial. Major holidays and Fridays are often the most crowded. The day/s after a major holiday and the middle of the week are often the least crowded. But call and ask. Don't assume.

They will know these things, they keep track, and are more than happy to see people shift their visit from a crowded time to a less well attended time. It helps you have a better time and helps them out. Ask about discounts for off-peak visits.

Ask about discounts every chance you get. Visitor services and courtesy centers usually know all the inside tricks. Too few people use what they offer.

Disney and associated businesses offer a multitude of discounts. But they aren't always big on letting you know about them. Most of these places have some sort of military discount. Many have a first-responded discount. Teachers and students may get a discount on some days. Senior citizens often see discounts. But you have to ask.

Going to a particular gas station, eating at a select restaurant, or staying at a hotel before you get to Disneyland may get you a small discount. Keep receipts. Some of these offers are good. Others not so much. Paying extra for overprices services to get a minuscule discount is no bargain. The offers direct from the Disney visitor services office are usually well worth it.

Keep a single use packet of your favorite headache remedy in your pocket. That and a couple of bandaides are all the FAK you need.

Don't bother carrying a full FAK. Disney has FAKs that would make you drool. Peek behind a few corners and you will find handy FAKs, AEDs, stretchers and fire extinguishers. They give people with EMT training and advanced lifesaving certification preference in hiring. They keep emergency personnel on hand. Disney may be an overly sanitized and plastic version of the world but it is also very safe. The entire place is set up for grandparents and small children and making sure they are protected.

Such places often strike me a cloying, saccharine, and artificial. The trick for adults in these sorts of places is to bring out your inner child. Be silly and childish. Forget reserve and being cool. Be silly, make a game of everything. Relax, laugh, cue off of the setting. If pirates are the theme; be a pirate. Have fun.

Down here in Florida we have Disneyworld. Several times the size of the Anaheim operation and a bit closer to the equator. The sun can be brutal and walking distances are considerable longer. If you do the Florida thing plan accordingly. You can stay a day at Disneyland. Several days at Disneyworld.

Anything more than three days of Disney theme music is consider cruel and unusual punishment that may entitle you to refugee status in the Netherlands.