“Glee’s” Lauren Potter will be making two appearances in the area this weekend to support Best Buddies, Anthony P. Shriver’s group. On Friday, the actress, who has Down Syndrome, will visit with the Best Buddies chapter at Washington-Lee High School in Arlington. Then on Saturday, Potter will attend the 3rd Annual Audi Best Buddies Challenge, a cycling fundraiser on the National Mall, expected to draw 2,500 participants.