Click on 'View Cart' (above) to see your items, or click on 'Checkout' to pay and proceed. You can also remove items from your cart if you wish.
You can continue shopping from any page of this website and then click on Cart/checkout (in the menu at the top, or on any resource page), when you have finished.
The cart/checkout links are also at the top and bottom of each page where resources are available for purchase.
I use PayPal to manage online purchases, but you don't need an account with them.
You can pay via credit/debit card at PayPal's checkout by choosing 'Check out as a guest' or 'Pay with debit or credit card'.