To start an infographic, it would be better if you work out the idea of it on a paper first. Then comes the information you are giving. The information should be properly researched and the facts should be accurate for your infographic to have an impact on readers. 52% of all the infographics have inaccurate facts.
Next is the presentation part. The information contained therein should be easy to read and not confusing at all. Also keep the fonts large enough to read on any platform. To make the it more interesting, use images like steak instead of pie for pie chart.
An infograph has no rules as such but keep these things in mind while making one.