Is there parking at the park or do i have to park off-site for fireworks? What works best to get out onto the interstate easily?

There's Street parking ( goes fast ) also you may think about Metro Transit ( lefant Plaza Station -- it'maybe a CenterPoint) To The Fireworks .. I am sad that This year Trump has seemed to screw up this year celebration. Keep in mine You & Family will be able to see it from The DC and VA side - good luck as this year will be Very Different

There is street parking. Depending on where you are coming from, you may use 395 or 66.

There is a lot in the center of the soccer fields and some along the street as well. Very easy access to the highway from there.