Hello,
I am doing really easy thing now, the line. Everything was good, everything functioned but only at my home. At diferent conditions (material of board where is another line etc.) it was not working. My friend told me that I need calibration or something like that. I want to read values from light sensors and then use it in source of line. The problem is that i did find nothing about that in lots of tutorials, helps. I am really new in this world and I am not native speaker.
I think it has to look like this:

than I want to use it in source for line
Is it possible to do it like that? I was doing somtehing in brix comand center but its something totally diferent for me.
Thanks for help

It looks like you have the right idea, it may be the ROBOTC syntax that is holding you up. No worries, though; we have a Video Curriculum Trainer available for scenarios just like this one. I would suggest going through the videos, which will introduce you to ROBOTC, its syntax, controlling motors, and how to use sensors (among other things). There is even a segment dedicated to line tracking that you may want to look at (found in the Sensing -> Line Tracking segment).

I would work through the videos and modify your code as you go; if you still have questions afterwards, we are always happy to help out!