A "Waiting" contest means you are waiting for the maximum number of players to join your contest. Once a contest has started by the first player joining all future players will join the same contest. So you should not be waiting that long.
A "Void" contest sucks, unfortunately, this happens when not enough players join a contest within 24 hours of the first player joining. However not to worry if this ever does happen we will reimburse you the full amount back into your GameStake Wallet.