And generally with what exactly was done here
Specifically, much has been done here on three.js (Yes almost everything). Brakes mainly come from the same tool, but rather from the fact that they are a little overused where you can do everything easier.
as a web designer with knowledge of html, css and a little jquery to do this?
Parallax pictures, text and gradient backgrounds for partitions; change of labels and plus - svg animation; videos on the background; a bit of css transforms for transitions between pages SPA; accordingly, the router, the practice shows that in such situations it makes sense to write your own, custom; scale on the right - even css transitions on the pages of projects and agencies - large pictures, a video, a little svg animations, a lot of absolute positioning, a little effect scrollfire + css-transitions; somewhere in between - uploading resources Ajax. If to divide all this into separate tasks, then this site will be quite feasible, the main thing - not to complicate the blue.