TikZ is a drawing package in LaTeX. It is very useful to draw a professional-looking diagram. However, the learning curve is a little bit steep for a beginner. I have recently compiled a 629-page cookbook that provides step-by-step illustrations on how to use TikZ to draw various diagrams in economics:
The book is available through Google Play or Google Book. You can read the whole book through free sampling. Of course, you are very welcome to consider buying me a cup of coffee by purchasing the ebook.
After purchasing, you may copy code directly through Google Play (only benefit of spending your money) and you can download a pdf file of the book but the pdf file does not allow search nor copy.