Adding Tempo instructions

My first score using Musescore! I am trying to indicate the tempo "Adagio" in a frame on the left hand side above the first bar, as is usual in scores. I have tried inserting a vertical frame, but after double clicking all I can do is change the size of the frame and there is no apparent means of entering text. I notice on the Pictures at an Exhibition that the frame containing the tempo instruction text can not only be edited but dragged into the desired position. This is not explained in the manual, and I cannot find any reference to this - a convention in scores in any of the toolbars. Please help me get started!