To post questions or answers in a forum you must register. When you click on the sign-in button you will be presented with a list of choices. Note that to scroll horizontally through the sign-in choices you must use the little arrows (that are a little difficult to find). Hopefully you have a sign-in with one of the applications shown. If not you can create one and then return to the forum page. Once you have signed in it is easy to return to the forums.