Thanks for getting in touch!
Exciting to hear that you are looking into getting a theme. First, we will need to login to the Shopify Theme Store located on the top right of the page. You can search for the Canopy Theme using the search bar. Once you find the theme you are looking for, we will need to select on Try Theme.
Do keep in mind, theme purchases are non-refundable so take a look at the demo before you make the purchase. If you are satisfied with preview of the theme, you can select the option Buy Theme located towards the bottom of the page. Selecting this will allow you to make the purchase and have it added to the themes in your store.
Let me know if you have any questions.