It also depends on how complex you want your designs to be. I will load up the files and link the YouTube walkthroughs I made (screen recording with audio over top). Credit goes to Lars Christianson with Autodesk, who did the same thing in Fusion, and where I got my idea from.
For background, my seventh graders have gone thru a bit of drafting/drawing, and look at orthographic representation before getting into this. The "back-story" is this is the only part out of R&D, and we need to measure and draw it in CAD, so we can mass produce them. Gives them a reason to duplicate a common part.
Instead of making them draw an orthographic representation, I give them a computer generated one (from my master file), a set of calipers and a radius gauge. They then need to fill in what measurements they think they need to make this in CAD. At the end of the lesson, they have three colored markings. One for original measurements they used, one for measurements it turns out they didn't need, and one color for ones they needed but did not have initially.
So for supplies, you need a measuring tool (we used 6" digital calipers), radius gauges (optional), and one 90deg fitting. I "think" this is the size we used (
Home Depot 90deg conduit adapter). You could probably do this just with just the videos, but it helps to have a hands-on part to work from. Especially if you are going to be building stuff later, and having to measure it.
