I to would just use the name of the park (except Magic Kingdom) to get you in the general vicinity of the park. From there, I would follow the street signs to get you to the parking lot. In general, I've found that Disney World is very well marked with directional signs and it's often easier to follow those than a GPS (the GPS sometimes wants to use back routes or restricted access roads).
For the Magic Kingdom, you'll need to use an address to get you to the TTC. I would either use the address for the GF or the Poly because those will get you to the main parking gate for MK and then from there, follow the street signs (stay to your left) to get to the parking lot.