Minneapolis Parks and Recreation urges adults to sign up for fall sports leagues. Register at www.teamsideline.com/minneapolisparks. Here's what's happening in Northeast: Pickleball Leagues: Mondays-Thursdays, four weeks in Sept., Windom Park, 2251 Hayes St. NE. Beginner, Beginner Plus, Intermediate, Advanced leagues available. Cost: $40 per two-player team (sign up as team). Intro to Pickleball Classes: Tuesdays and Thursdays, four weeks of two-hour sessions in Sept., Windom Park, 2251 Hayes St. NE. Intro to Pickleball, Intro to Pickleball II. Cost: $80 Indoor…