I'm planning at trip for my gf and some friends down to Disneyland for a day
I'm assuming you mean "Walt Disney World", the massive park complex near Orlando, Florida (Magic Kingdom, EPCOT, MGM, Animal Kingdom, Typhoon lagoon/blizz beach) and not "Disneyland" - the small California theme park.
Florida Residents get a MASSIVE discount.
Unless traveling with children, I suspect that you will spend most time in EPCOT. A group of 3 20-something adults managed to go through every park, and see at least 40% of each park, and ride a number of rides in a single day. However we were EXTREMELY exhausted afterwards. Walked something like 15 miles that day.
It is not that childs play to get from park to park, so have an actual destination, and stick to it, lest you waste the park hopper.
Now that i typed all that I see you are going to the cali park. Oh well, hope this helps someone someday.