If we (have) a skatepark in my neighbourhood, I (not skateboard) in the street.
If we had a skatepark in my neighbourhood, I wouldn't skateboard in the street.
If there (be) a community garden, we (grow) our own vegetables.
If there was a community garden, we could/would grow our own vegetables.
My dad (go) running every morning if the park (have) a running track.
My dad could/would go running every morning if the park had a running track.