One place to go? Ride the Bay Trail from Point Isabel to Richmond's harbor. It looks like this:
We stumbled across a birthday party at this park where everyone got a kite to fly. It looked like so much fun!
And we found this kayaking class where they were learning how to get back into the boat after falling in the water. They didn't paddle anywhere, but kept tipping themselves into the water and climbing back in.
And then we headed south east again, back to Point Isabel. It's flat the whole way and easy for all levels of riders.
If this isn't your thing, head out to Point Pinole. Or Coyote Hills. Or just go find the water. Just go.