Friends telling me to buy lee sin

He's fun.

Depends IN order to master some champions you have to understand alot about the game

Lee HAS a high skill cap, but a low skill floor.

Meaning it does take a lot of practice to get the most out of him, but he is also pretty easy to pick up and play at a competitive level quickly.

edit: He's also pretty safe and is one of the easier jungles to gank with which makes him a good beginner pick. I would see hecarim and sejuani right now, theyre pretty strong atm and are also easy to pick up.