Peruvian Spanish is some of the clearest that you will hear in Latin America. For this reason many travelers choose Peru as the location to learn Spanish. Having said that, there are also bazillions of slang words that are used by locals. Here is a list of some of the slang that you might hear bandied about on the street.
Lucas - A slang word for soles. For example: "Necesito 20 lucas para mi entrada" "I need 20 soles for my ticket."
Cocos - Slang word for dollars. Use as above.
Chevere - Awesome
Bacan - Awesome
Chamba - Work. For example: "No puedo ir al concierto tengo mucha chamba." "I can't go to the concert I've got a lot of work on."
Chibolo/a - Young person
Jato (HAA-to) - Home
Pata - Mate, Pal
Pituco - Snob
Porfa - Shortened version of por favor please
Porfis - Same as above
So there is a start for you. Memorize and use these and you will sound like a native Peruano and have everyone impressed with your grasp of Spanish done Peruvian style.