The GOAL program is a great first intro. However if you cannot make it, there are some clubs that offer a 'new shooter' program that's an intro to the basics of the game - mostly safety oriented, as safety is the most important thing.
You can go to IDPA’s website (
www.idpa.com) for some basic info and also find a list of IDPA affiliated clubs in the area and links to those club websites. In MA we have:
Rod & Gun Club of New Bedford in Dartmouth, MA
(
www.rodgun-nb.org/ap/action.htm)
Riverside Gun Club in Hudson, MA
(
www.riversidegc.org/IDPA/IDPAHome.htm)
Agawam Revolver Club in Southwick, MA
(web link not working)
S&W in Springfield, MA
(
www.downzero.com/site_home.aspx)
Bass River Rod & Gun Club in Yarmouth, MA
(
www.bassriverrod-gunclub.com/IDPA/MainPage.htm)
In addition, just about every club will do their best to accommodate new shooters. Just let the match director know when you arrive. They will give you some of the quick safety things and probably pair you up with an experienced shooter who will be your mentor and guide you through the different safety rules, tips on how to handle different targets, range etiquette, range commands, etc.
You’ll find that action pistol shooters (IDPA, USPSA, etc) are a bunch of friendly folks who are more than willing to help new shooters. If you think about going to a match just to watch, might as well bring some gear so you can shoot.
As for what caliber is best… ask 5 shooters and you’ll get about 12 different answers. Best bet is to start with what ever you currently have. Go and participate in a match and ask different shooters what they are using and why. You’ll probably get offers to try their equipment too. Then you’ll have a better idea of what to get.
Good luck. Hope you come out and play.