Cal here from Shopify, thanks for reaching out to us. I've had a look at your store, you've done some great work so far. I've made a few suggestions that you could take into consideration:
1) Get a logo designed for your store: You can use Hatchful (http://bit.ly/2Xcmhw1) to design a logo for free!
2) Insert a favicon into your theme when you have your logo created.
3) The 'Collectibles' section seems to be tacked on, as it doesn't seem to fit in the 'health' niche that you were going for. Do watches match what you are trying to achieve with the store, or are they just put in because you think they are nice products?
4) Landing Page content: The homepage could do with more images and more text. The About Us, however, should be its own page with a link to it in your navigation. The landing page should suggest who the business is and what your mission is (what problem are you solving?).
5) Social Proof: If you have social media accounts for your business I would strongly suggest putting them in the footer of your theme.
Right now your site is very product-focused, without communicating essential components like branding and business objective. You've done a great job on your first store, but have a look at what competitors in your niche are doing and emulate that as much as possible!
What marketing strategy have you for the business?