"We are a very nice bunch of blokes."Quote from Steve Shaw.
my experiences with you on the net do not confirm this, however if I was to meet you in person, I could very well find you are in fact a nice chap.
There are a small percentage of good rhythm players around, what I would ask of beginner percussionists is please go away and learn to sing the tunes, next listen to a tune once through at least, before joining in, secondly play quietly to an unaccustomed tune.
I do not want sessions to be exclusive, but a session cannot be musical anarchy, people do have to listen to each other, it is considered session etiquette, to listen to the person who started the tune, and follow the way they are playing, and let them lead into the second tune of their choice, please rhythm and melody instruments listen listen listen.
beginner percussionists practise playing along with recordings, if you go to a session regularly, get a list from one of the melody players of tunes that are played a lot then... go away and listen to recordings of them, and play along to these recordings, or get one of the session players to make a recording for you