We are a low key group and range in skill from beginners to intermediate. Anyone/Everyone can participate.
All you need to bring is yourself and a Frisbee, if you have one. I do suggest sunscreen/sunblock and water.
I, Carrie, typically show up late, @ 6pm, and sometimes cant make Thursdays, but the group plays anyway. Look for a guy (Numan) in the A's hat behind the baseball field and you will find us. Fyi, we do have a separate meetup group for our casual games: http://www.meetup.com/Casual-Ultimate-Frisbee/
We usually play until dark, but not always and may end up grabbing food afterward :)