For the most part the parking regs can be figured out with a little common sense and some looking around. There will almost always be signage if there are restrictions. Asking locals is always a good bet too. If you are friendly and respectful when you approach someone, they will usually tell you what is cool and what is not, regardless of what the posted regs say.
The carts are a good idea but I really only used mine a couple of times in the beginning. For the most part, I can pull up to the launch, dump the yak and then drive to the parking spot.
When fishing is a part of a friendship, you can skip right past the preliminaries