You don’t have to touch any code to arrive to that result, everything is already available inside sections add-on.
I think that the only thing that you have to install, in case you don’t know how to write html is this: https://wordpress.org/plugins/lightweight-grid-columns/
for the columns in the second and latest section.
For the darker images, that’s something really easy to accomplish with photoshop, gimp or even https://pixlr.com/editor/