Howdy Ryan. To be more specific, I'm in Santa Ana. For your first bit of travel trivia Anaheim is where a large German population settled in the late 1800's and they combined Sanat Ana and the German word heim for home into Anaheim, Santa Ana being the next town over.
First off do you have any idea what you'd like to see? Do you prefer art galleries or being outside? How adventurous are you with food? And, what's the rest of your 26 days filled with? Having said that, Disneyland is in Anaheim and it's always worth a visit. Also there's this:
http://www.missionsjc.com/historic.html
There are a series of Spanish missions in California and the one in San Juan Capsistrano is about a half hour from Anaheim. It's easily reached by train with a stop right across the street.
I'll wait till you get back with what your likes and dislikes are because, depending on how your time is alloted, you could visit anywhere from Santa Barbara to Las Vegas(where you could double your money) to to Mexico to a quick trip to Palm Springs. Also, if you're not aware, the drinking age here is 21.