I am new to road biking (less than one year), but i want to challenge myself and find a fairly fast group ride (20+ mph). I have found a few rides this saturday that start in Irvine. The food park one looks good, but i have heard its a huge group. I dont know if thats the best one to try for my first group ride? I also heard OC wheelmen is a good group, but do i have to register before i ride, or can i just show up and tag along? Any feedback would be appreciated.