Brakes are acting WEIRD + Oil leak?

[Rommy]

I asked my friend, he said I might need new rotors.

It's more than likely likely that I need new pads as it is (That's no problem, $15 a pair at AutoZone), but I'm scared that my car won't stop when I need it to, right now. I press the brakes, and I get a sick vibrating, almost like the ABS is constantly engaged, but I don't even think it has ABS. Are the rotors warped or something? It's like, a "BRRRRRTTTTRTRTRTRTRTRTRRT" when I press the brake. Please bear in mind that I'm a retarded 18 year-old who means well, but doesn't know much about cars.

Also, as for the oil leak, my father and I were changing the spark plugs (Really helped, just changing two of them, lol) and the whole thing where the spark plugs are was like, 1/4th full of dirty oil. Is it possible for oil to leak into there from somewhere?

(I have a 1990 Supra, non-turbo, if that helps any. I'm just really lost here. )