How to gain muscle cheaply?

im 6ft 2 and weigh 10 stone really skinny i want to go gym to gain muscle but cannot afford it and have no knowledge about what protein etc to get all i know is the good ones are really expensive. i eat ok i wouldnt say brilliantly i have breakfast a meal and snacks like toast and chocolate in between.for excersises i have a weight bench, dumbells, a chin up bar any recomendations on a workout routine or proteins i can get and do would be much apreciated thanks.