u/ILoveFries25

It’s right next to a big compound, is it a farming base or just like extra storage or smth

Bought a used bike on facebook marketplace, and rear brakes didn’t work very well so I started messing with them then this thing popped out. The front brakes are what it’s supposed to look like if anyone wants a picture of that. But I’m pretty sure I need to take the black cord off and string it through the silver thing on the right side of the second pic. I’m a bike beginner and not really sure how to fix it or if I should just take it to a shop. Any help appreciated!