I was always involved in the PTA's at each of the schools our daughter attended. I was a PTA President at 2 of the schools I was also an Executive Board Member for our city wide PTA.
Yes, there is a small fee, plus we added a fee to cover the cost of the paper we would be using to send out the newsletters.. (this was before most people used email).
At the elementary level our PTA had the reputation of being cliquish, but I realized it was just that some of those parents had been at the school for so long and knew so many other parents and all of the staff and teachers that had been there a long time also.. They had 3 to 4 children, so they had been there for up to 12 years together.. !!!!
Can you imagine?
Anyway there area always some people any where with insecurities and can come off as being standoffish, but work with them on a project and they open up..
Begin by volunteering on things that sound interesting or things you have skills at. Then you can watch and see what else looks like you want to put your effort into.
Middle school is where most parents disappear. Their excuse is that their "children do not want them to be there.". I used to tell them to tell their kids, "do not worry, I am not there to see you, I am there to help the school." Of course the middle schools are where you are really needed.. they never have enough volunteers.
Once you get to High School, these are your last 4 years with your children living at home. They are getting ready to decide on College and there is again a lot of things the schools need help with. Also the "Class" your child will graduate with, begins raising money for their Senior year activities, because usually schools do not really provide any money for the Prom, Graduation Night events. etc..
I now have a huge group of Parents that we met through the PTA that we are very close to. Some are my best friends, many were also the teachers and all of the Principals..