I am trying to make a directory for a library using K2. The default K2 template is not useful as the order Title / Image / Description is one under the other.

Where can I find other themes and especially one that put Image at left and Title & Description at right?

You can browse our available K2 Templates here: www.joomlaworks.net/joomla-templates

I don't search for a Joomla template... I am talking about K2 template...

All of our templates are built specifically with K2 in mind.
Since Joomla! is the CMS, they are all typically Joomla! templates.

maybe I am not clear...

I want to customize the way that K2 is showing items on Category view.

I need a "template" or "theme" so the specific category in K2 to look different than the others. Specifically I need the "Image" to be at left and "Title" and "Description Text" to be right of "Image" in Category View.

If you want to customise overrides, then you need to override K2's default template.

This post will show you how to override K2's templates getk2.org/documentation/tutorials/174

that's my point... so there are not ready customizations?

This depends on the template you are using.
If it has multiple K2 sub-templates prebuilt.

If you want to drastically change the layout of the item (eg divide the content on seperate columns) and the template you are using does not offer this view, then you need to manually adjust your overrides.