That little wheel in the middle of the mouse? Eon's dad compares it to a car wheel — and rolling it is called scrolling.
Roll forward, roll back
You can scroll the wheel forward and backward. In a 3D program, that's how you zoom: scroll one way to move closer to your model, the other way to move farther away — like walking up to something to see the details, then stepping back to see the whole thing.
A little warning: it can feel backwards
Eon's dad gives an honest heads-up: the zoom direction is "not as intuitive as you might think" — sometimes forward zooms the opposite way you'd expect.
The fix is simple: just try it. Scroll, see what happens, and adjust. Poking at a tool to learn how it behaves is exactly what makers do.
Try it
If you have a mouse with a wheel, open any map or webpage and scroll up and down. That same wheel is what Eon uses to fly his view in and out of a 3D model.