If you have registered as a customer, you do not have to log in to buy anything. Registration simply saves you the bother of filing in the details at the checkout each time.
If you can’t remember your password, just click on “Forgot password?”(below the login box) to be sent a new one.
Also, please read this post: Customer Notice
Order 5 or more of any items in the shop to get 10% off the price!