Could you please help me? (sorry if this is a bit off topic) I am not
technically minded, but I would like to start an online store. What
should I start with? Are there any pitfalls that I should be aware
of? Thank you

Before you try to accomplish much. Are you going to want to except credit cards?

There are some great scripts out there. I have looked into getting a store on my website so I have looked around.

HotScripts (http://www.hotscripts.com/) is one of the best places that I found. Another good site is PHP Resource Index (http://php.resourceindex.com/).

Hope that helps you. :)