Gallery title
Straight forward enough. Add a title (above) if required, enter some supporting content into this RTE property if required and then select some images for your gallery using the media picker below.
Clicking the image opens a full-screen modal window and you can navigate through the gallery.
Settings Instruction
Hidden toggle: shows/hides block
Background colour: Adds a background colour to the whole block
Navigation title/Anchor: creates an anchor link that you can use to link to from a navigation object e.g. url#anchorlink
CSSClass: you'll not need to use this
Remove gap: Remove the top padding from the block so it sits tight to the preceding block.