What happens if dogs get into a fight at a dog park?

I just got a new dog yesterday. The home he was living in had two other dogs who he got along fine with, and the neighbor also had a dog that he got along with, so I’m not really too concerned about it, but I plan on taking him to a dog park and I just want to have an idea of what would happen if he got into a fight with another dog.

Does someone get fined? What if another dog picks a fight with him? Are there any legal repercussions?