Olde Town Arvada hosts a free concert and street fair every second Saturday of the month in the summer, which should land on Saturday, June 14.
Golden, Colorado is just a 10-minute drive West of Arvada. It has plenty of outdoor activities to offer from easy to hard hikes, tubing down Clear Creek, walking or biking the paved Pleaks to Plains trail, or touring the Coors brewery.
From Olde Town Arvada you can hop on a quick 20-minute Light Rail ride to Union Station. From there, you are within walking distance of museums, shopping (including the flagship REI), and restaurants. You can also take the free mall ride from Union station through town along the 16th Street pedestrian mall.