Help increase conversions on my site

Hello warriors.

In my first attempt at any form of internet marketing, I've set up a shopify dropshipping store.

Cartooncase.us

I am selling iPhone cases and have managed to get 3 sales since the site launched a week ago.

Now I know 3 sales isn't much, I consider it a huge victory considering I am completely new to the industry and by no means have any experience with web design or marketing.

I got 3 sales by running facebook ads for $10 a day for 3 days netting a total of 150 visitors and generating $37 in sales, or $7 profit. (Its probably worth noting I am working with little to no budget)

I took that profit and spent it on an instagram shout out from a marvel super hero page with 200k followers and good engagement.

I would have carried on with the facebook campaign, but saw no more sales after the first day, and would have started losing money.

The 24 hour promotion (which ends now in 2 hours) got 568 people to my site, but not a single purchase. Lowering my conversion rate from 2% to a fraction of a percent.

Looking at my site, is there any pointers anybody could give me on how to increase my conversion rate? Clearly I know I could use a professionally made logo and images, which I am working on.

Thanks for your time
-Dustin