Steps:
1.npx create-react-app shopifyreact
2.git clone https://github.com/Shopify/storefront-api-examples
3.cd storefront-api-examples
4.cd react-js-buy
5.yarn install
6.Update access token and Domain
src/index.js
const config = new Config({
storefrontAccessToken: 'your-storefront-access-token',
domain: 'your-shop-name.myshopify.com',
});