You don't need a PayPal account to buy WCT tickets! After you select your dates and seats and go to the "Check Out" screen, fill in your name, email address and phone number, and then click on the orange "Pay Via PayPal" button.
You'll see a screen like this one. Click on the "Pay with a credit or debit card" option, and PayPal will collect your card information. If you have a PayPal account, it will "encourage" you to use it (PayPal makes more money that way), but you can decline and stick with the card.