No. Logging in is only necessary for customers who do not want to enter their billing information more than one time. You get a login when you make a purchase and select "Checkout and register". In step two you enter your email address and a personal password that you use next time you make your purchase.
If you don't want to create a webshop account then select "Checkout" and click the continue button and you will be forwarded to the next step in the check out process.