Congrats on getting married!!!!
You are very smart to ask around for advice because that is Memorial Day weekend and many people will have time off and go to the park. I used to live close to
Disneyland and would often visit in the afternoon/evening after college classes, so I recommend on your afternoon you are going to be so excited to be there but don't wear yourself out! Maybe go to Disneyland and claim a spot for Paint the Night and the fireworks, go on a few rides, and then go to Downtown Disney and shop or just explore the area around the Disneyland Hotel. If you like to enjoy a drink, Trader Sam's is a lot of fun! There's also a wonderful buffet at the Grand Californian.
On one of your full days you should go to California Adventure right when it opens and get a fast-pass for World of Color. Then head over to Disneyland and try to work your way through the more popular attractions first, before it's crowded and hot. Also get fast-passes every time you are able to. They might run out toward the end of the day, so get those early.
Don't miss Mickey & The Magical Map show, it's fantastic! If you are looking for a mid-day break away from crowds and heat, head to one of the resort hotels for a meal, or you can get on the train and ride it around the park while you relax your feet. Make sure to ride it in a complete loop at least once. There are some unexpected things to look at. If you are at California Adventure, Animation Academy has several walk-through areas and it's all indoors (with A/C!) and if you just hang out in the atrium area they have Disney music and art, and I like to just sit back and enjoy it while I rest my feet.
I think 2 full days and 1 afternoon will give you enough time to do everything you want, as long as you plan ahead (fast passes!) and prioritize. You will have so much fun.
Also stop by City Hall and get a couple "Just Married" buttons!
