How to start writing, where to get help?

I have started to write code for e+e- -->mu+mu- at energy s =\sqrt 500 GeV. But I could not proceed and get confused.
Also when I try to use ROOT in Jupyter notebook , it shows “kernel starting, please wait”, but it never starts. How to fix this problem.
Please help me.
Thanks in advance

ROOT Version:_ v6.20.06
Platform: Linux mint
Compiler: Sublime


Do you see any error in the console what could point to what the issue is? It could be a problem with the installation of ROOT or some missing package (metakernel is needed to start the ROOT C++ kernel in Jupyter).

Thanks a lot