I'm looking for a longboard and have no idea what kind to get?

Go to your local surf shop and explain your situation to them. They hear it all the time and are trained to give you the board you need. I would suggest a 9 foot to 9'2'' longboard. You don't want to go to long because you are so small. As far as brands, it doesn't really matter. As you get better you will learn what type of board you like. As a beginner you just want a board that is sturdy and will float you. Plus you will probably crash a couple of times so you don't want to get a really nice board when you first start out. Best longboards are Guy Takayamas