The First Order is based off remnant Imperials that fled to unknown systems after Jakku. There was something out there (Snoke?) and they’ve had 30 years to design and build new ships, train troops from infants and make plans. Their first major offensive took out the Republic capital and most if not all of the Senate and a large part of the fleet. They are an invading force.

I wouldn’t mind seeing them attack civilian cities and the like. We never really saw that in the OT or the PT.