Lyric discussion by blitzmut 

Cover art for Here It Goes lyrics by Jimmy Eat World

I get the feeling of a high school dance or a disco back in the 70s or 80s where circles used to form around single dancers who would show off their moves. Saturday Night Fever sure comes to mind. I picture a kid who's been trying out all his new dance moves in his room all week between work or school or whatever - and he's been waiting to become a star for those 15 minutes on the dance floor at the local club or whatever. In a much broader sense: practicing over and over again to make your debut with confidence, almost cockiness and then nailing a performance of some kind. The title of the song seems to suggest that "Here It goes".

forgot to add: Cut to the left and slide to the right could easily be references to the DJ's turn tables (change the cut you're playing on deck one and slide the crossfader to deck two).