This community is primarily structured around the sort of subjects you would see in an academic setting, but learning skills is absolutely within the scope of this community. If you have any, please consider commenting with free resources and advice for things like playing an instrument, learning a language, woodworking, etc.
For automotive repair the 3 best resources I’ve found are youtube, buying a Haynes repair manual, and the ALLDATA website. Youtube has videos for doing most things on your car/truck, a Haynes repair manual walks you through a ton of basic to advanced procedures (it pays for itself), and repair shops use ALLDATA. It’s more advanced and a bit less intuitive but a great resource. I get it free through my local library which is great too!