Take her bowling,ice skating,aquarium,art museum,amusement park,arcade/ resteraunt,bumper cars,surfing lessons,go canoeing,rollerblading,a broadway show,haunted house or haunted mansion tour,drive in movie
The trick is to avoid commonplace. Do something that she won't do again any time soon. A symphony, concerto, live play, or an opera. A renaissance event, or something like that. If those are above your budget, then try going online and check on live events near some towns near you. Lots of towns and cities have their annual festivals around this time. Take her to one.
Look up radio stations you both listen to have an events calendar many times free or low cost events. Local newspaper has entertainment calendar and community events calendar and often have a free or low cost event section. Look up community or city or county web pages have events calendar. I found among the boring stuff is just the right free event. Go to every web page of every surrounding city-community. It takes some work but when you find the right event to impress the girl it is worth it! I have found some cool car shows. They were small shows but it started out the date. Also go to the tourism page of the state you are in. They will have a calendar of events in your local area that are free or low cost.
Look at all these possibilities.....! How about an afternoon walk around a nice part of town, maybe a little, little, little dinner, not fast food, maybe... salad?, and on until just after dark. MAKE SURE YOU ARE IN A OKAY PART OF TOWN AND GET HER BACK... Im just playing safe, maybe go to some historical locals, popular places, Parks , take a soda, the "Main Street" that lights up at sunset... get the idea?