Just practicing and I must've clicked on something I shouldn't. My layers have disappeared. I followed the faq's and looked in dockers, it's checked but greyed out.

Screenshot? Without more info, helping is going to be kinda impossible.

Look at the right side of the toolbar, (right top of the program) there is a button that shows the workspaces, choose Default one and the whole window/dockers will go back to normal hopefully.