How to slow down/stop the car?

I have recently learned driving. I can drive confidently on straight roads.However, I panic and my car stops ,when in a narrow lane or if I am riding upwards on the slope, a vehicle comes from the opposite direction. I apply clutch and brake both so that car's engine doesn't stop. But more often than not, my car's engine always stops and I have to start it again. It is very embarring and problematic especially when I am driving upwards on the slope because there are vehicles behind my car.I want to know how much pressure should I apply on clutch and brake, when I am in second gear and I want to slow down or halt at the side without stopping the engine of the car to give way to the opposite car on the narrow road?