Hi Denise, Welcome to Barnmice. It's a wonderful and informative way to wile away the winter hours. As far as the groups go check out "dressage fanatics" and there is another that discusses the science of equine motion. I can't understand half of what they are talking about but I struggle along.
I think you'll find the caliber of the riders/trainers that you'll meet here is quite high. I've made friends with a woman in Canada who has three students who are coming to the US to ride this Spring to qualify for ...something. I'm easily impressed. Show me someone who can ride thier horse past a chicken and I'm impressed.