Paypal and bitcoin are pretty much the same thing. But if you are shopping online paypal would be the better option.
Paypal is worldwide better known and therefore used for online webshops.
BTC cann't be properly compared to PayPal until we have a system like the Lightning Network up and running. Until then, Bitcoin will still be seen as a extremely robust form of money that replaces gold and not something you would use on the daily basis to buy good and services.