Sign in to your account, or Sign up with your email from the main menu.
Then, enter account details to fill in your details such as names, user and password (important action).

Login to the store and Add to the shopping cart the products selecting available options. Ahem: color / size / quantity. 
After of adding all products "Go to the shopping cart"To apply a promotional coupon (if you have one) and / or"Finalize purchase”(Both available in the main menu icon shopping cart)

Enter to finalize the purchase and register or update your data, and proceed to pay.

Enter to finalize the purchase and register or update your data, and proceed to pay.