In addition to everything else listed, just....how to do basic things. Especially for men whose biggest reason for not doing very basic things is that they don't know how/were never taught.
I'm talking how to cook stuff that's not from a box, or at least how to spice up boxed stuff like how a few spices and some veggies added to pre-packaged ramen can make it not only more filling but tastier and at least somewhat healthier.
I'm talking how to do laundry, something I see a lot of adults just not knowing how to do. Why it's important to separate your whites and colors, what the different tags mean, how to make your own laundry detergent for cheaper than the store stuff.
While we're on clothing, teaching how to hem/adjust clothes and do repair jobs is a very useful skill that I've never seen taught unless one parent already knows how or special classes are taken but it should be a more widely taught skill. Saves loads of money if you can go shopping and find something a little too big for you but know how to adjust it to fit, especially if you're thrift shopping.
Basic troubleshooting for household appliances is also something useful but almost never taught. I know how to reset our garbage disposal if it stops working, for example. I know how to unclog just about any drain with simple home remedies. And I know when it's time to call a professional after I've tried a few different things that do the trick 98% of the time so I can save time and money doing those first.
Also how to clean stuff. Effective ways to vacuum and do dishes, how to clean a toilet and bath tub, those kinds of things.
All stuff that the internet taught me more than my mother or school or any other source and I had to adjust to as an adult. And all very useful skills that are actually practical for the real world regardless of your job or just about anything else.