I'll be in Gettysburg next week for vacation. We go about 3 times a year. Plenty of things to do there.

Get some canned goods and fresh fruit at the round barn in Cashtown.
http://roundbarn.farm/

Have some wine and sit on the patio and listen to some music at Adams winery by the roundbarn. They have events on the weekends.
http://www.adamscountywinery.com/

If you can, take a battle field tour on horseback. It is easy, and an excellent experience. Really a must do.
https://confederatetrails.com/

See Eisenhower house on a park tour, and a civil war hospital in a barn. Campfire story by park rangers is free and usually very good at Pitzer Woods in the park. Climb the Longstreet tower on Seminary Ridge, and then go a mile or so down the road to Sach's covered bridge - both free and neat. Climb inside the PA memorial to view the battlefield from the Union viewpoint.
https://www.nps.gov/gett/index.htm
https://www.nps.gov/gett/planyourvisit/interpretation.htm


Good places to eat
http://abcbrew.com/

http://www.dobbinhouse.com/

http://garryowenirishpub.net/

http://food101gettysburg.com/

https://the-pub.com/?utm_source=tripadvisor&utm_medium=referral

https://www.facebook.com/Blue-and-Gray-Bar-Grill-246227418780785/

https://www.tripadvisor.com/Tourism-g60798-Gettysburg_Pennsylvania-Vacations.html