I try K2 now for several weeks but I simply don't know how it works.

It seems a extension for me which has a quite steep learning curve so I would like to know where I can find some proper manuals.

For example, at the moment I't trying to get my articles in columns but whatever I try I still have them in one column.

Those simple things I would like to solve out with good manuals.

Who has some advise?

This
getk2.org/documentation/k2class2012
is the best reference to date on K2, it covers a lot of topics.
Please be more specific about exactly what your trying to do and send a link if your site is live so people can take a look at what your doing.
As far as i know, there are no written documents

These kind of manuals are very usefull.

Thanks for the answer.