I'm sure it will be fine. I probably won't be the best or worst prepared, but even if I am, the nature of the curve is such that someone has to occupy the last spot - so be it. Today's goal: showing up. Not puking. But I'll accept just showing up and call that a success.
I am so not the person I was in high school, who swore I'd never take another exercise class after dragging myself thru PE hell. I can, for example, imagine this being fun. I hope I'm not disappointed, but this is also about making a plan and executing it.
Even if the plan is just: show up.