Once ONOS is installed and running, you can start accessing it through different interfaces.
The ONOS CLI is the primary user interface with the platform. It is useful and easy to use, and it allows to run the majority of the commands.
ONOS has a GUI that can be accessed through the IP address of the target machine, from any browser.
where XX.YY.WW.ZZ is the IP address of your target machine. The default username and password is onos / rocks.
This is just a few places to start. Look at the following guides to to learn how to interact with ONOS!