Some paint chipped off on my 06 Toyota Coralla (thanks god not on my crossfire). I think it was caused by a bicycle or stroller crashing on it when it was parked on the street. about 3 cm long, 1cm width, exposing the bare metal. Today I spot some rush started on that area.

I want to know what is the correct way to fix it. also regarding the touch up paint, are there any difference between the one from toyota and other brands (speaking of quality, not color matching) Thanks.

Second update:
WORSE THAN I THOUGH.....

So the area in the middle is bare metal, with some rust started. But I found something worse. The surrounding paint is also chipping off, the paint doesn't stick to the car, and I can easily peel it off. What should I do???