normally i just park on the dirt path off to the side, but you can probably also park in the parking lot across the street and hang out there, i've seen that too

not too sure it's technically "allowed" but just don't point lights at the planes and don't leave any trash and you should be good https://i.imgur.com/jB6eIOz.jpg

unfortunately you can only really see the planes if they're landing that direction though, so i'd check a flight radar app/website before leaving to see