A. When I try to get at the essence of "Hello World", it's the minimum that must be done in the programming language to generate a valid program that prints a single line of text. That suggests to me that your "Hello World" should be a univariate data set, the most basic thing you could plug into a statistical or graphics program.
B. I'm unaware of any graphing "Hello World". The closest I can come is typical datasets that are included in various statistical packages, such as R's AirPassengers. In R, a Hello World graphing statement would be:
plot (AirPassengers) # Base graphics, prints line graph
qplot (AirPassengers) # ggplot2, prints a bar chart
xyplot (AirPassengers) # lattice, which doesn't have a generic plot
Personally, I think the simplest graph is a line graph where you have N items in Y and X ranges from 1:N. But that's not a standard.