A quick search found the following two articles: configure file contents and How do I change my admin password?

These should help get you started, but I would highly recommend also reading the Zen Cart documentation (especially the implementation guide). I've found the documentation along with the members of this forum to be very helpful! So if you have additional questions after reading through the documentation feel free to ask

There are also a published book (e-book format) and some video's available on using Zen Cart (see the Zen Cart home page).