The Queen's Gambit Declined
There are two new Daily Tournaments for practicing the Queen's Gambit Declined opening
Under 1500s sign up here:
https://www.chess.com/tournament/u1500-queens-gambit-declined-tournament
Over 1500s sign up here:
https://www.chess.com/tournament/1500-queens-gembit-declined-tournament/join (apologies for typo, site doesn't allow amendment to the tourney name)
Games are RATED, and there is 2 days per move. They are small tournaments with only 5 players, so you won't get overloaded with games.