My MacBook doesnt charge

Ok so i just bought a early 2009 macbook pro 15inch model is a1286.. Long story short i got ripped off. The mac was telling me the battery needs service, guess i need to change it.i used it for 2 days. Worked perfectly, connected the the charger obvs. Last night i left the charger connected to my mac and this morning the charger light wasnt on. And before it would go green before i would connect it and then go orange..this is my first mac, so i dont know if thats a sign or w.e. i also noticed that the charger and on the connecting port on the mac are of a brown-ish color.. But only on the 2nd last prong...i need help :(