I don't like much dog parks. IMXO, it is not safe for yorkies. Last year one yorkie was killed by retriver in dog park. Yorkie wanted just to say "hi"

. It happened in first seconds. Both owners were just shocked

. The only exception is one park where we go all the time. It is NOT an official dog park, all dogs must be on leash, however all owners let their SMALL dogs play and run. We don't have many big dogs.
Usually, we prefer to go to other parks with no dogs.