Search the forum for any relevant posts on your question.
First, search the forum for any relevant posts on your question. If there aren't any, you'll need to start a new thread. A post is an individual question or reply, a thread is a series of posts in reply to an original post. You'll need to join to post, but it's quick and free to do.
Post new thread
At the top and bottom of each forum section (board) is a 'new thread' button. Click on it, enter your text and click 'submit new thread'. For more on how to post, see the New to Forum? Youtube guide.