Based on the weather of the past couple of weeks, it looks like we are in for a long, cold winter.  If that is the case, there's a chance you'll step outside one day to a car that won't start.  Temperatures in the teens and lower can easily kill your battery.

Outside of staying home or calling a tow truck, you basically have one option.  That is to borrow the juice from a car that is already running.  You will of course need a set of jumper cables, and someone who is willing to volunteer their vehicle.   Once you have that resolved, has some easy steps to get you car up and running.

Move the running car as closely to your dead one as possible, preferable with the front ends facing each other, or next to each other.

Connect the positive jumper cable to the positive terminal on the good battery, then to the positive terminal on the dead battery.   Then connect the two negative terminals.

Keep the car running for at least a minute before you attempt to start the one with the dead battery.

Try to start your car.  If nothing happens, check the cable connections to the battery terminals.   If it  doesn't start after a few tries, that's bad news.  You'll probably need a new battery.

If you replace the battery on your own, you should wear gloves and safety glasses.