Whip It is based on Derby Girl, a 2007 novel by roller derby athlete Shauna Cross. Cross also wrote the screenplay for the movie.
It's a move used during a roller derby. Specifically, it is when a skater grabs a teammate's hand/arm and is pulled forward, "whipped" around and in front. It builds speed and helps her get through the pack.
Bliss' t-shirt (which once belonged to her mom) is for a band named Stryper. Stryper was a successful Christian-glam-metal band, playing from the mid-to-late 1980s to 1992, with a reunion in 2003. They have an official website.
It's called "The Power is On" by The Go Team!
The rest of the songs and their corresponding scenes can be found at what-song.
