@Sam198
Guests use the booking service, so are charged for it.
If you want to see what that looks like, go to a listing and enter some dates, and you'll see how it's calculated. For some areas Airbnb has been made to collect certain local or gov't taxes. For Amsterdam Airbnb charges the 5% mandatory Touris/hotel tax for the city.
The website has clear info on what they charge. Have a look around. Also more detailled information pops up when doing an online search with Airbnb, fees.
If you still need to orient yourself on the ins and outs of hosting on ABB, go to the Hosting Discussion Room on this forum and check out the first post. In it is a link to Community help guids - extremely helpful for new hosts.
Hope this helps.