Every man, and even a lady mustachian who can turn a wrench should learn some basic car car and maintenance.
This includes, learning to check and change your own oil. (Seriously not difficult folks). Learning to know when, and how to change your own breaks. Properly greasing fittings and joints. Knowing how to replace radiator fluid and how to check it. Knowing how to check brake fluid. Knowing how to change the fluid in your transmission. (Typically only ever needs done at 100K)
Knowing how to clean battery terminal posts. How to jump start your car properly. How to rotate your tires. You should know your what the tire pressure is suppose to be for your car and how to check it. (Hint it's not the PSI rating on the tire, but whats written on the drivers side door, sometimes the door post.) You should know how to change a flat tire. How to replace your fuel filter and air filter.
How to replace a fuse and change the lightbulbs on your car is another great one to learn.
Buy a Hanyes Manual for you car. Buy some mechanic gloves, unless you like greasy hands. Get some tools. LEARN by DOING.
Here's another hint, buy your motor oil at Walmart. But do not buy their cheapo brand, it is GARBAGE. However I have noticed autopart stores purposely sell incorrect amounts of motor oil at higher prices than Walmart sells on the self.
For example, Walmart sells a 5 Quart jug of Mobile 1 for $15.00 on average, and over at Autozone, they sell some weirdo 1 gallon jug (That LOOKS JUST LIKE THE ONE AT WALMART) that actually is actually 4 quarts, and most of the time it costs more. So you'll need to actually buy 1 quart off the shelf, which typically costs $3. This is deceptively annoying IMO. I actually only buy my filters and parts behind the counter at these places. I refuse to buy any fluids from them.
So there is my advice. Car Maintenance is important. But remember folks, its CALLED THE STEALERSHIP for a reason.
BTW, those $15 and $13 oil changes, are probably putting the cheapest POS oil filters and oil into your car, possibly ruining it, doing damage to the engine and decreasing the operating lifespan of your vehicle. They are not worth the time of day.
DOCUMENT everything. This sounds silly and pointless, but you can use it for leverage when you want to sell your car. You just pull it out and go, here is when everything was done to the car. BAM. Then people know the car was well maintained, and you can charge more for the peace of mind they'll get.