Hi, Amanda!
There's a great post entitled
Parking Fees at Walt Disney World, so be sure to read through for answers to questions you may not have known you'd have!
Basically, you'll pay one fee for the entire day of parking, no matter how many parks you visit in that day. Currently, the parking fee for a car is $14 / day.
In general, Guests will park their cars in the space indicated by the Cast Members helping in the lots, then will walk to the nearest tram stop. Hop onto the tram which will take you to the park entrance; it's that simple!
If you get the parks early in the day or during an off-peak season, you may even be directed to a spot that's fairly close to an entrance, so you may not even need the tram, too.
Send more questions as you think of them, Amanda! We love to help!