How does joining a club/training work?

I've been looking into Schutzhund with our eventual new puppy, and I'm trying to figure out how training works. I understand requirements for joining various clubs and all that, but what I'm trying to figure out is how one would actually start training and how it works when training days are just listed as drop in. Are there starter classes or anything like that, or do you just have to show up hoping someone will be available to help you? Is it normal for new members or people new to the drop in training to be new to the sport, and have no prior experience? I'd really love to get involved, but I'd feel bad showing up and taking up people's time! I'm honestly not the most outgoing person in new situations, so I don't know how I'd be showing up looking for help. :blush:

Also, I've been looking at Topline German Shepherd Club in Willowbrook, IL, does anyone here have any experience working with them? Even though my current dog (rescue husky) is an adult and pretty decent in household obedience, he's never been through an actual class, so I was thinking of taking him through one there just to see how everyone was and how everything there worked. Any personal experience of how things are there, though, would be appreciated.

Thanks so much for the help!