Ways to earn Money Online

How to I buy something from a person in the US?

I have no clue where to start or how to pay or what.
I’m buying a paintball gun from him for 130 dollars US, I live in Canada and haven’t the slightest clue on how to make the whole transaction
Do I send money in an envelope? Do I pay online or make a money transfer somehow?
I’m only experienced with buying from online sites with my parents’ credit cards, with their consent of course. And Ebay sometimes I get my mom or dad to do it. I have a bank card that I may be able to hook up to PayPal.
Just tell me exactly how to get the person the money, and how to get me the gun including stamps and stuff and ALL you know, because I don’t know shit as far stuff like this, its a home adress as is mine. Please Help
Thx-
Eric

I dont know about this, but he can eBay it, and but a buyout and you need to instantly bid on what he put. But I have never used eBay, so I wouldnt know.