TNT would be perfect for you . There are chapters everywhere. Do a google search for team in training and you can go to the main website, put in your zip code, and bingo. I had never ridden in a "peloton" until I started with the team. Now, it makes so much of a difference, especially on long rides. Just the fact that you have someone to talk to makes the miles fly by. As to avg speed, they break you up into 3 groups, at least my team does and I'm pretty sure all do the same. You have a Gold Group ( avg 18mph +), a Green Group ( 14-17 avg), and a Purple Group ( 14 and under avg). Most people can fit into one of these categories.
Good luck on the road