Is this a good first car?

Just make sure you find one that has been well maintained and not beat on daily for years. A 91 is an old car so most likely they all will have pretty high milege. Also you better have some more money saved up in case this car decides to blow up on you and you need some major repairs. I would look into a little newer year of a car since you will be able to drive it a lot longer till you are in college and can afford a newer car.