Q: I'm having some electrical problems with certain accessories on the car 1998 GMC Jimmy

I bought a 98 Jimmy and on the test drive I didn't notice anything wrong with it except the odometer light bulb was out which I thought was a fuse. Before I drove it home I put a brand new battery in it in the next morning before my grandpa went to work he tried to start it and it was completely dead. Will a week and a half later I got played funny and was able to drive it around for the day I noticed my driver low headlight was out and the driver's window was feeling like the motor was about to go out. My step-dad put a new bulb in the driver headlight and it did not work so he took the old bulb out of the driver's side and put it in the passenger side and it worked but would not work at all on the driver side. The battery voltage is not going down at all while the car is running or if the car is just sitting for a few hours but if it sits a long time like overnight the battery completely dies. I didn't notice anything weird going on when I turn the key. Is it the ignition switch?

My car has 123 miles.
My car has an automatic transmission.