Black & White
To make this page, I clicked on the Pages tab and created a page I called "Black & White (Gallery)". I saved the change and clicked "Black & White (Gallery)" on the main menu (above). I then clicked on the Multimedia tab at the top left and dragged the "Photo Gallery" icon under the Elements tab onto the empty page. I clicked on the gallery placeholder and clicked on Upload Photos. Once uploaded, the images can be captioned. I chose not. But I did want a title, so I clicked on the Basic tab at the top left, dragged the "Paragraph" icon to above the gallery, and typed my title.
Finally, I dragged the "Paragraph" icon to below the slideshow to create this note. Then I clicked Publish.
You could place more than one gallery per page, but why? when you can nest gallery pages like this one in a drop-down submenu. After creating at least one gallery page, create a "Galleries" page under the Pages tab. You can rearrange the order of pages you have created by dragging them up and down in the order. Drag your gallery page carefully over your "Galleries" page and you'll see it attach to "Galleries" page. Save this change and you have your first drop-down menu. Don't forget to click Publish. As you add more pages and content to your website, this is a good way to keep things tidy.