Check out MathMathMath's amazing tutorial first! https://scratch.mit.edu/projects/171039475/#player Use the WASD keys to move and the arrow keys to rotate.
I've been wanting a simple, easy-to-use 3D engine for quite some time, and MathMathMath's engine does the trick! :) So, I just went through the tutorial, modified a few things, and made it easy to play around with and remix. There are some things to add in the future such as rendering back to front or adding tri-fillers and such, but this is a good start.