Hello Aaron! A bit delayed here, life got hectic!
In regards to the Sidhe, my personal experience is to show them respect. I've never actively sought them out, as I viewed that to be potentially taken as aggressive. The interaction I've had in the past have always been one of the Sidhe coming to me of their accord. I treat with great respect and honor, and try to live in the moment and see where it goes from there.
I do leave offerings for the fae, and honor them in other more personal ways, and that's about as far as my experience goes.
I'm not sure there is much history for Druidry in Mass beyond maybe some secret sects... As far as OBOD, The Mystic River Grove is classified as the oldest OBOD grove in the USA.
There are other Druid groups in the area though. Tribe of the Oak is one, and I wouldn't be surprised if there were AODO or ADF groups as well.
I hope this helped both of you, and sorry for the long wait!