Talk about good mods to start with if they want to gain some experience.

You can try to categorize different playstyles and keep reminding new players the understanding of joint behaviour and still have fun while trying it.

If they're casual players that spend few hours on a game weekly, it's better to show them fun mods that keep them entertained where balancing isn't the biggest key factor.
If they're more gaming players that have no problems to grind on 1 single game, you can pinpoint more challenging mods and make them learn the basics of balancing and also stiffness.

What I forsee the most is how to not get trapped into certain categories when it comes to xspar, mma, aikido etc.
Each mod have slightly different purpose and understanding of how you should control your tori.

There's a good example of different mods that I can share with you if you need some guidance, with each of these have some kind of different learning techniques. Such as, timing with extending/contracting to avoid obstacles, prevent of DQ, etc.