Re: How to set up PayPal?
Sign up for a NEW PayPal business account, then setup your profile, funding etc and merchant services.
Re: How to set up PayPal?
When go to admin->modules->payment->Paypal Express for example, there are also some instructions about making those credentials accessible and setting up Zen Cart for customer use of PayPal. PayPal Express is the recommended payment module as there has been little issue with working through completion of an order using that method compared to other PayPal methods.