Oh Car Problems

For those who know me, know that I know nothing about cars and only recently found out that when it gets below zero that you have to plug in your car so that it stays warm and will start the next morning big shock to me since I have never lived somewhere where it gets below zero on a regular basis. Any way the battery in my truck was an older battery so after the night that I plugged it in and it still didn't start I went out and bought a new battery which my friend graciously installed for me since I had no clue how to do that. After he fought with installing it, we proceeded to fight with the truck to getting it to start for the last five days so today I youtubed how to replace a car battery took the battery back just to be told that the battery was fine and they wouldn't replace it so I brought it back reinstalled the battery with some help moved some wires for a better connection and it turns out the ground from the battery to the engine needed to be grounded better. Thank goodness for youtube I would never have figured out how to take it out or put it back in if not. So now I officially can replace a car battery if need be...You learn something new everyday