http://sinclairstudio.es/ Any ideas?
I know its canvas and stuff but wow.it looks really amazing
Creating this kind of animation is a little bit too complicated to be explained in one post. The best choice for you would be to go throgh some canvas tutorials and learn the basic principles. You can also look for some already made exmaples and analyze the source code. For example here. When you google try and search for keywords like ‘canvas fluid simulation’ or ‘canvas particles’. You can start from the very basic animations and then expand and gradually add more effects. And also be ready to do some math. There’s always math in complicated animations 
Sure, it’s cool, but the page took a solid 20 seconds to load. The website probably loses 80% of its potential traffic.
There’s a boat load of CSS in there as well as several js files, which you can see in your browser’s dev tools.
If you want to see neat stuff like this there are examples abound on codepen.io with all the code shown.