Please think twice about bringing your small child to the dog park.
It can be a scary and dangerous place for a child, even one who is generally comfortable with dogs.
Remember that the park is primarily a place for dogs to do dog things off-leash. That means run, herd, sniff, etc.
If you do decide to bring your kids,
1. Keep them close and
2. Never let them run
For some helpful tips about bringing kids to dog parks, see