Paypal is a place where you deposit and withdraw money - like a bank account. It is separate from HubPages. When you make enough money on HubPages ($50), on the 28th of the following month, HubPages will deposit the money into your Paypal account. Then you will log into Paypal and withdraw the funds.
To make sure that you have properly linked your paypal account with HPubPages so that HubPages can direct the money properly, just go here: