Tricia is the one in the maroon shirt w/ the white floppy flower hat (so 90s). She is easy to find because she is front-and-center during the most of the dancing segments and the camera loves her.
TJ, on the other hand, is a little bit trickier to find. BUT we finally found him. At the end, you'll see him in the back, wearing black, sporting a stylish bull cut, and in Tricia's words, "doing cabbage patch chugs with his arms and then a high school musical tuck jump."
Can't stop laughing.