Ok first you need to decide what mode you want to run in. The Nanostation can be in bridge mode or it can be a router if you don't have another router.
Here is a how to wiki if you want it in router mode.
https://community.ubnt.com/t5/airMAX-Configuration-Exam...
If you want it in bridge mode you can still follow the instructions but will want to change the network mode to Bridge. If you still have questions come back here and ask. I am using a Nanostation Loco in a similar setup and should be able to help.