For the type of airplane you are going to build, you can balance the plane with your fingers and measure the throws with a ruler, as guys above have said. A trainer is not that critical.

If you are just getting into building, there are a number of items that you will find a lot more useful.....such as a Dremel Moto-Tool, a soldering iron, a jig saw, a belt sander (table type--great invention!) and maybe a hinge-slotter...and the list goes on.

For now, have fun creating an airplane out of a box of wood and parts!

Clair