This website gives a few recommendations of basic car repair books. I took a look at some reviews, and it seems like Auto Upkeep: Basic Car Care, Maintenance, and Repair by Michael E. Gray and Linda E. Gray might be a good place to start. From what I saw, it's used as a textbook in some introductory auto classes, so it should give you a good baseline without being too condescending.
For basic questions, Car Care Kiosk has been really helpful for me. You put in your car's make, model, and year and then choose what you need to do. It gives step by step instructions with a separate short video for each step. It's really helpful, as you can re-watch the specific video you need to see again instead of skipping back and forth in the same video. As you get more advanced and want to start looking into more technical procedures, Chilton is a very respected name in car care. They're pretty much the encyclopedia for car repair. They used to print huge manuals for each make and model of car with detailed instructions, but now they've mostly moved online. If you have a BYU login, you can also access the Auto Repair Reference Center database, which is also very detailed.
My main advice is to at least know how to check your oil, your coolant, your tire pressure, and be able to change a tire. In my opinion, those are the absolute basic skills every car owner should have before they get out on the road. There's also a lot of other things that are a little below surface-level car knowledge but are actually really really easy. These include: changing your windshield wipers, replacing burnt out headlights, replacing your engine air filter, and replacing your battery. I don't actually know how to change the oil in my car, but I've been told it isn't too hard. I'm sure there are more really simple upkeep things that you can do, but this is what I've figured out so far.