Maybe try http://scanftree.com/programs/c/programs-to-print-pyramid-patterns-in-c-part-1/. It starts with very simple examples and their code. You could copy that code and if you're doing this on a PC with a nice Integrated Development Environment, you can use a so-called debugger to go through the lines of the program and see step-by-step what happens in each line.
Pattern printing is usually a means to learn programming as it requires basic algorithmic thinking, i.e. deconstruction of a problem / pattern and using this analysis to write the loop with the proper indexing (synthesis).
I'd consider it a training for, let's say, more useful programming as graphical patterns can oftentimes easily be represented non-algorithmic.
Or if you want to master pattern printing first: learn the basics of loops and indexing. They will enable you to do some simple examples from which you learn for the more advanced ones.