A park hopper to do both and only being there one day is rough. To do both means you can only hit the highlights and even then, to get in as much as you can, you will have to be there from park opening to closing. You can easily spend a day at each and still not do it all, even then. Being your first time going to any park, and only having a day, personally I would recommend just doing a single park, Disneyland (where it all started).
You will enjoy Disneyland because of myVMK. While VMK was built off of items in multiple parks around the world, a large portion of it is based around Disneyland. As you walk around, you will see things and be like, "Oh my gosh, it is actually real". That's why I recommended Blue Bayou restaurant as a place to eat because it is like it is in VMK.
Be sure to read up on Fastpasses, because you will want to use them if you can (ticket to come back to a ride later and get on quicker that allows you to go do other stuff).[DOUBLEPOST=1428803712][/DOUBLEPOST]If you decide on a restaurant (sit down), call as soon as possible to get your priority seating reservations made.