The episode that we have is evidently the THIRD one. On the first day, we missed TWO episodes (at least according to wikipedia.)
This is what wikipedia said:
1 January 5, 2007 The Cave of Many Voices
Chomper's secret cave in the Great Valley becomes leaky and the Gang goes exploring in the deep caves to search for another suitable cave for Chomper to live in. Meanwhile, Ruby teaches Ducky how to act and talk big. The song Adventuring is reprised.
2 January 5, 2007 The Mysterious Tooth Crisis When Chomper loses his tooth, he and Gang decide to travel around the Great Valley to figure out what is wrong. Meanwhile, Cera, Spike and Ruby relax in Tria's secret mud spa. There are no songs in this episode.
3 January 12, 2007 The Star Day Celebration Ruby misses her family on her "Star Day" (a.k.a. birthday) and the Gang tries to help cheer her up by being true friends and bringing Ruby her favorite food.
Remember, this is wikipedia; what we see has to be considered carefully.
Also, in episode one, we probably learn about how Chomper and Ruby have come to be in the valley, and in the second episode, when the caption says "spa", it probably means "hole."