I LOVE LOVE LOVE LOVE Disneyland! I love it so much in fact that in the past 2 years I have been 3 times and have an upcoming trip this September. I would encourage anyone, anywhere, anytime to go there. It truly is the most magical place!
Though my experience I have come up with some tips I think might also benefit other people.
You must do both parks. I like Disneyland way better than California Adventure (C.A), and still, every time, we do both parks. Why? Because if Disneyland didn’t exist C.A would be my favorite place on earth, it’s still that good.
Learn how to use the fast pass system. Especially for rides like Radiator Springs and Terror Tower (in C.A.) and Space Mountain, Splash Mountain (in the summer), and Star Tours (in Disney)
You do not have to stay in a Disney hotel. I have stayed in multiple ones nearby, my favorites being the Alamo and Discovery Inn for a super cheap stay. Or the Anabella for a fancier but still cheaper option.
Skip the park hopper. Decide which park you want to do that day and just stick with it. You waste time leaving the park and re-entering another park. There is just more than you could ever do in one trip (hence why I keep going back) without needing to jump from park to park