Hi
It is very easy to use, first you will create category, similar to joomla and afterward you will create item similar to joomla article. After doing it , publish it
To displaycontents in your website, go to menu and create a menu item with k2 options, After publishing menu you will able to display category and items created with k2 component.
I will hope that it will help you to start using k2 component. If you have any specific problem then please post your problem in forum.
Best of luck