My car wouldn't start

There are a few things to check. When you get in, is everything dead? No dome light, dash, etc? If so, it could be a few things going on. Let's start with the easiest one to check. Have the battery tested.. if it is good,, get it charged. Start the car. Once it is, disconnect the negative power cable. Does it stay running? If yes, then your alternator is fine, move on. If it dies without battery power then your alternator is bad, and drains it while running. I don't think that is the case here, as you didn't mention any issues taking it to the house.

If it stays running, then time to see what else might be going on. You might have to have a friend do this if you don't know how. You need to shut the car off and do a DC amp draw. When you do this, make sure you have a charged battery (auto parts shops often charge for free) and make sure your car is completely off. Doors closed, etc., and give it a minute or two after to make sure all lights are off inside. Because all of that will give you false high readings. Do the amp draw, and see what it says. I don't think you should be pulling more than ~20-25milliamps. If you're pulling more (especially if it is much higher) than something is draining your power when its off. Best way to find this is leave it hooked up, and start pulling fuses, one by one. Pull.one out, check meter, replace. If one of those fuses causes the power demand to drop… check what that fuse is for (either owners manual or fuse box cover) and you'll have your answer as to what is draining your battery.