Hi,
I´ve done a research for this and couldn´t find anything about it, maybe I wasn´t looking correctly. Any how, I want to creat a template for my articles where the actual layout chages, lets say I add 5 extra field (don´t know how to do it) I would like them to appear en the right side of my article on a box just as I show in the image I edited. Could please someone have the patience to explain me how to add the fields and make them appear as I want them to?
Thanks,
Ivan.

These videos will help you get into K2.
The extrafields are located from "Extending K2 Through Plugins Part 1" and onwards.

As for creating subtemplates and overriding (which you have to do in this case).
You have to read these posts.

getk2.org/documentation/tutorials/174-templating-with-k2-and-the-concepts-of-sub-templates

nuevvo.com/blog/item/84-k2-inheritance-sub-templating