Hey taurus :)
Depends on how you want to participate. If you want to join in as an investor, you can participate in the token sale at https://www.arcona.io/.
But I'm guessing you want to join in as an AR content creator. For that, once the Arcona Digital Land is up and running, you can purchase digital land anywhere in the world. After that, you can create AR content and place it on your plot. The team explains that they will provide tools to make the AR content with ease so the mass market can participate. Alternately, you can purchase the AR content. Then depending on the popularity of the plot you bought and the amount of interactions it drives, you can generate ad revenue, much like you would from a popular webpage.
Hope this explains everything.
Thanks a lot for such a great information regarding AR @hatu you explained very well.