It's okay, we asked for help, too.
The Houston Astros, and the New York Yankees* will play the first Wildcard game this evening at 8PM EST. The winner of this game will go on to the play the Kansas City Royals in the American League Division Series (you will hear this referred to as the ALDS.)
*Big news: one of the Yankees best pitchers will miss the playoffs to attend rehab.
The Pittsburgh Pirates (who have been bad for a long time) play the Chicago Cubs (who haven't won a World Series since 1908 and are generally believed to have been legitimately cursed by a goat) in the second Wildcard game. The winner goes on to play the St. Louis Cardinals in the National League Division Series (NLDS.)