leaks should be pretty obvious.
You also shouldn't be driving it until it gets fixed. Unless you are an asshat that likes running the risk of rear ending someone just because you were a dumbass.
brake leaks go from "not that bad" to "totally blown out" without warning.

check inside the car to see if the fluid is dripping down the firewall. if it is, then it is the master that's bad.
Look at all of your wheels. If it is the caliper, it should look wet on the inside of your wheels. even just a little bit is way way too much.
If none of that is leaking, then start tracing the lines. The lines can rot out/ rust out, especially if the car used to be a northern car.