Park and ride is when you go to a parking lot, leave your car there, and then get on a big bus or train to go to another place. It's like going on a very long car ride, but with a different kind of vehicle.
Sometimes people use park and ride if they live far away from where they want to go, or if they don't want to deal with the hassle of parking in a busy city. It's a good way to save money on gas and avoid traffic.
When you get to the place where the big bus or train drops you off, you can explore and do fun things. Then, at the end of the day, you can get back on the bus or train and ride back to the parking lot where you left your car. It's like having a chauffeur take you on a big adventure without having to worry about driving and parking.