Okay so i have a question about protein bars/shakes?

Okay so i go to the gym early in the morning, im usually there for an hour and a half to two hours. and when i get home im really hungry i usually have oatmeal or a fruit smoothie. But i was told by a friend that i should start drinking protein after i work out. So my question; is it bad if i have a protein bar/shake for breakfast? i've never had protein after a work out? so what do you guys think its the best type of protein? thank you :)