From an SEO standpoint, the best thing you can do in the short run is to ignore it completely...sort of.
What you need to do is stand back and take a hard look at the usability and structure of your site.
Is your code up to snuff? No validation errors, tableless layout, etc.
Are you using heading tags correctly (or at all) to describe the sections of your pages?
Is your cart easy to navigate and traverse?
Are you using any querystrings (e.g. id) that are noted for being search-engine-unfriendly (strictly an SEO issue, but if you code it right you can make your URLs slightly more user-friendly as well).
Do you have a shipping policy?
Does your storefront have a theme or does it have an Amway sort of feel to it?
Are you using any kind of "CMS" that would create URLs that are both user and search-engine unfriendly?
What you should actually do is ask for a
website review, since the issues I've mentioned can affect both your user experience and your SEO efforts. More people tend to look in there, so you'll get a lot more of the feedback you're ultimately looking for.
For a first site though, I'll at least say it's not a bad effort. I did much worse my first time out (fortunately for me, the site is no longer on the Angelfire server which it resided on back in 1997.

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