Hi,
The credit card payment plugin allows you to collect the credit card data of your customers in order to process the transactions with your own payment terminal.
So the transactions are not automatic and you need to already have a terminal on your end to process them yourself.
For automatic transactions, you need to have a merchant account with one of the payment gateways supported by HikaShop (you can see the list in the "payment plugins" section of the HikaShop documentation page) and configure the corresponding payment method.
PayPal is a solution, but HikaShop also supports more than a 100 of other payment gateways so the choice is yours based on your country, the fees you're ready to pay, the practicality of the payment gateway, etc.