You can change this area's text by editing the "Frontpage" page in your admin's Pages section. You can also replace the "Frontpage" page with another page in your Theme Settings.
Write a few sentences to tell people about your store (the kind of products you sell, your mission, etc). You can also add images and videos to help tell your story and generate more interest in your shop.
To edit the content on this page, go to the Pages section of your Shopify admin.