Yes, basically all you need is a PayPal account. The documentation¹ provided by PayPal is rather clear, so I suggest you first read up on that, before looking at the Perl modules.

In a nutshell: Your customer makes a payment, PayPal's server posts the data to your script, your script checks it and returns the data to PayPal.

A nice thing is that you can test this in the PayPal sandbox²