@Rene120 try this link Refer Hosts (airbnb.com). It should take you to your personalized links.
However... there was someone on here last week who said they had referred someone and not gotten the credit, and they were told the program was closed when they called Airbnb for information. I can't find anything about it online. If you're concerned, I would call Airbnb or message them on Twitter @airbnbhelp for clarification.
Referral and Ambassador Terms and Conditions - Airbnb Help Center
I've referred a number of people and never received anything. There are a lot of loopholes on a good day.