Collect customer e-mail before Checkout details in Shopify

I have a shopify Store. Once Customer clicks on Checkout, I want the first step to be only to enter his e-mail info, so we can use it for abandoned carts and only once the e-mail is entered move forward with the normal checkout, making sure he doesnt need to enter the email another time. Start your bid with word CHECK OUT, but make it as a single word, so I know you've read the description. Have more projects to work on if this is sucessful experience