The ceremony location is about a 10-minute walk from the Nassau Avenue G train stop, assuming the MTA is feeling ~generous~ that weekend and running the train. The B48 Bus also drops off directly in front of the park. Consult
this website closer to the date if you are planning on using public transit.
Rideshare is probably the best option and may be the easiest choice, especially if you’re coming from farther away and dressed up.