Click the listings tab. Below the photo section there is a property type section that should give you a drop-down menu to select the correct type. If this doesn't help, let us know where the error comes in.
The best reference for Airbnb policies and process is the Airbnb Help Center: https://www.airbnb.com/help. It has a very intuitive search function and the articles are written in simple language. I recommend that you bookmark it. I did a search for "property type", and this was one of the top search results: https://www.airbnb.com/help/article/317.