Thank you for the quick respond in the first place :)
And with "print" i mean something like the serial monitor from the arduino.

Can i use mycontroller on my Rpi 3 with openhab at the same time ? I'm new to this stuff.

I make a project in my engineering class and i just try to receive the first data from my light sensor node. Can i print the data on my gateway or do i have to connect my Raspberry pi 3 to it?
When i start the sketch, all the LEDs on my gateway start to blink.

Secondly i don't really know how to set up my OpenHab Rpi 3 as a controller to mysensors.

And my last question is: What does these colums mean? I understand some lines but i don't know what to do with the information. Currently i have an arduino with an NRF24 module with the SerialGateway Sketch and another arduino with the light sensor Sketch.
Thank you in advance :)