It will mean more than 170 pupils moving to the Portadown campus from September 2020.
The shooting happened at a house in the Connolly Place area of Lurgan.
A brick was thrown at the Lurgan Presbyterian church and Remembrance Day crosses were damaged.
Former Sligo Rovers and Derry City defender Seamus Sharkey joins Glenavon on a two-and-a-half year deal.
The front door and hallway of the house were damaged in the fire, police say.