Can I accept course purchases with both Paypal and just a credit card?

PayPal allows you to make payments using different methods like your PayPal account balance, a bank account, PayPal Credit, debit or credit cards, etc.

You can follow this link for steps on how to integrate PayPal into your account

With PayPal payments on onlinecoursehost.com, your students are not forced to pay you with their PayPal account. 

They can still pay via PayPal without creating an account with them, simply by presenting their credit card.

They can also pay by all sorts of methods available in the student's country, such as debit cards and other types of payments.

So using PayPal for one-time payments is usually more flexible and convenient for students.