I agree, glammanana Yes, you see the same names cropping up in some discussions, but that is because they are interested in those subjects or involved in those areas.
New voices with something to say are welcome, and only some of the people who post a lot are the "founder members". Stick a toe in the water on a thread that interests you - possibly saying "I am new here, but....." There are so many threads that you will find several that are for you. If not, start another. Someone, somewhere, will answer.