You can learn basic programming from Kaggle

Root package: https://root.cern.ch/

Root Geometry package: Link 

Drawing options in ROOT: https://root.cern/doc/master/classTHistPainter.html

Learn basic programming (C, C++, python): https://www.programiz.com/

Python in HEP Scikit: https://scikit-hep.org/ 

Learn perl: https://learn.perl.org/

debugging tool: gdb (http://learn.onlinegdb.com/)

HEP software foundation: (https://hepsoftwarefoundation.org/)

Statistical Method for LHC (RooFit and RooStats) (https://statisticalmethods.web.cern.ch/StatisticalMethods/)

Linear algebra toolkit (http://www.math.odu.edu/~bogacki/cgi-bin/lat.cgi)

Quantum computing IBM (https://quantum-computing.ibm.com/docs/)

One code in different computer languages: https://rosettacode.org/wiki/Rosetta_Code 

Bayesian analysis: https://github.com/chunshen1987/bayesian_analysis