SEO to increase sales of a new e-commerce.

I need help with SEO to increase sales on my e-commerce www.lensbotic.com done by shopify.
It is a new store that has not got any sales yet.
If you have any suggestions of how to drag customers from Facebook and other social platforms that would be very much useful! I would like to know roughly how many visitors I can expect the next couple of weeks/months. Since we are a start up our budget is limited, we are looking for someone that can help us out as a fun project and work with us long-term