(custom?) particle physics

I found this very interesting video, but I'm quite new to unity and have no clue how one could create something like this:

1. How would I create particles like that?
2. How can I apply forces to the particles?
3. How can the particles form an image?

I would love to learn as much as possible about this topic, so please spare no details.

Thanks alot!

(i hope this part of the forum is the right place for this post)

 

it's a pretty advanced subject, maybe download some asset store plugins and checkout their code to see how they are doing it?