SquareSpace does make it pretty easy to have a great looking website up and running in just a few minutes.
I still spent half an hour needlessly confused over one thing.
SquareSpace has both a page type called ‘Gallery’ and a content block called the same. The former is best thought of as an organization tool; the settings available are limited by the specific template you’re using, and often don’t include visual controls you might expect – like changing the number of columns and the padding between images.
Those controls *are* present in the ‘Gallery’ content block. The content block can be populated either ad hoc, with whatever set of images you want, or display an existing gallery collection (page).
So if you can’t make your SquareSpace gallery look the way you want, you probably just need to add an extra step to your process – and put a gallery (page) into a gallery block.
For more on this, check this SquareSpace help page I somehow missed when I began my journey of discovery.