Extras => Galleries => Create a new gallery.
Enter the image directory here from which you would like to create a gallery (that is, you must move all the pictures that you would like to have in a gallery into a folder using "Files").
Next, select whether you would like to have a
Type 1 gallery (gallery with thumbnail pictures to browse through) or a
Type 2 gallery (slide show).
Below you can then make various settings such as font size, font color, etc.