Hi and welcome among the «Scribenti»
I do not think there are templates availbale for a «catalog».
I suggest you start designing a layout double-page with Writer (or Word) (or just by hand) and publish this layout here. We might be able to guide you through.
However, it would be much better, you try first to get to terms with Scribus and explain also, what kind of experience you have.
It is also necessary to know how many pages your work will have.
If you speak German, you could make a dedicated Scribus introductionary course at
http://www.gimp-werkstatt.de/forum/viewforum.php?f=96