Thank you Vyacheslav for your quick reply. I am nearly there, but would have found the following useful.
To create an album, you will need the “PRO” version on your site.
Having created a gallery, click on it and then click on the “Settings” button and tick the “Album mode” and save.
You now create and select a category under which you will create one or more albums.
Click on the +category and you can create a sub-category, which we will now call an album.
Now insert or move the relevant photos into this album.
When you view your gallery on your web site, you will see a new album, showing how many photos are in the album. But the album image will be a black square by default.
To have the album show a picture instead, then you need to……?