Gallery No Longer Working

Hi

I have got the following message at the top of my screen (I am a novice at these websites but have put together ours for my Brass Band).

Any help much appreciated!!

The following files ‘gallery-template.php’ and ‘gallery-single-template.php’ were not found in the directory of your theme. Please copy them from the directory /wp-content/plugins/gallery-plugin/template/ to the directory of your theme for the correct work of the Gallery plugin