your best bet is to see what clubs are with in your range to drive to. Check thier web sites or go directly to the clubs (many clubs have breakfast or weekly dinners and meetings open to the public) as some do not have web sites or the information on the web site.
You can look for CMP affiliated clubs in your area and look up clubs that have sanctioned or aproved matches BUT some clubs have CMP shoots/clinics that are not listed on the CMP web site as they dont shoot for scores to be recorded.
Hanson rod and gun club hanson MA is one example they shoot CMP/High power 1st Sat and 3rd Sunday every month but that will not show up on the CMP web site.
Also You could check into Reading Rifle they have CMP and NRA matches along with other events that for the most part are open to non members.... CMP and NRA are open to all pending maybe safety issues.
the CMP web site sucks so when i get home I will look it up