Don't become someone else instead just be yourself and post in a discussions that you know of. If you didn't know that topic then don't reply.
If you can not answer questions, don't post.
If the question is already answered, don't post and repeat answer.
There are some threads made by newbies asking questions and a forum user already gave an answer but there are still other forum users who still answer the same questions. This happens when the first answer is not complete or some are additional to the previous answer.