Ok this was annoying to figure out so here you go.
I was trying to create 2 axis graph, or chart, in Excel since the relationship of the data was not very good. one was in the tens and the other was in the thousands.
First create a graph using your data and select the type you like. in our case it was a 2 line graph.

then right click on the smaller graph, the blue one in our case, and select the “Format Data Series…”

Then we get a popup window for the series options with the ability to change the series axis.

We select the Secondary axis option and close the window using the Close button.
The graph will update and set for 2 Y axis display.

P.S. the process can be repeated for more lines and more Y axis.