Hi, I am new to joomla, and heard that k2 is best used for mag site, so i installed it but each time I write an article using k2, it does not display. I tried importing my core file but still no progress. And am stuck with asking myself why. Please can someone help me out.Thanks.. NB: Pls can someone be my guide, I really need to learn how to use joomla and k2.

By making a category and putting items in it you are half way there. You also need to have a menu item linked to that category or item.

You will also need to take extra care of the parameters of the category to be set correctly.

Take a look at the documentation section.
Maybe you should also read a little bit about joomla first here.