The first shows of outdoor concert season in Maine are finally on the horizon, with Old Dominion at Thompson’s Point in Portland on Thursday, Anderson .Paak at the Maine Savings Pavilion in Westbrook on Sunday and Lynyrd Skynyrd at the Darling’s Waterfront Pavilion in Bangor on Saturday, June 1. In most cases, concertgoers won’t have any trouble getting into a venue with their tickets.