Optimizing air-flow in a room
 

I want to optimizie the air-flow in a room & im new to star ccm.
What should I do? Should I follow the simple flow tutorial? if yes, should I change the values & properties?

The tutorials are a good starting point.
You can play around with the parameters from the tutorials and have a look what happens.
For the air flow in a room, you might have a look on gravity and ideal gas (for buoyancy effects) and maybe (depending on your problem) unsteady simulations.
A lot of properties contain "expert properties". You should not twiddle with them unless you know what you are doing.