To start off, Gaudete is Latin for "rejoice". Advent is typically a time of hope and preparation, but it is nice to have a celebration of joy in between all the hoping and waiting.
Gaudete Sunday is not just for Sunday. It is for the whole week - Sunday through Saturday.
Your challenge for this week is to exercise the virtue of joy. Smile at as many people as you can. Be joyful! Also, continue practicing the virtues of hope and patience, because although it is a special week, it is still Advent, so we should still be practicing these virtues.
God Bless!