This can be removed via the theme language options, in the back end of Shopify, Themes -> besides Customize -> Actions -> Edit Languages -> Layout -> Bottom of the Page (from there you can also modify the Copy right)
You can also do it the easy way just through the Search Bar in Edit Languages then Search.
Other Useful Information:
How to Change Specific Texts - Change Specific Texts in the Theme
How to Change Specific Colors - Change Specific Colors in the Theme
Different Add To Cart Options - Change the General Add to Cart Button to different styles/ layout
Variant Swatch Style Options - Learn how to change the variants swatches to different styles.
Custom Link on ATC Button - Redirect the Add to Cart Button to a Certain Link