Yes, you either need to setup a page with a 'buy-it' button that you create at PayPal that will already be configured for payment to go into your account, OR you can log into your PayPal account and send a 'money request' to someone by sending the request to their email address, OR you can just give someone your PayPal email address and tell them how much they owe you and they can log into their PayPal account and send you the money that way. Typically, however, for businesses, they have a page setup with a buy-it button (at the very least - if not a full blown shopping cart that accepts and integrates with PayPal) to make purchasing streamlined, professional and easy for your customers. You need to make it as easy as possible for people to pay you, or else they won't do it.
It depends on your business and your products/services, and how many of those you have, as to what my suggestion would be - but at the very minimum buy-it buttons, but if you have several items, I'd go with a shopping cart -
http://mals-e.com is free and works with PayPal and gives you a few more options than just a buy-it button.