1997 Mazda MPV leaking

The first step is to find the point where it is leaking from. It might be a hose or a joint. A lot of times, the tension clips that hold the hoses to the radiator or other point of engine contact will wear through the hose and it will be leaking out of that spot. A radiator leak won't usually keep a car from starting, it will just get too hot. So what does it do when you try to start it? Anything?

Well before this leak, and it was a BIG leak, like my car would start but after turnin the key for like 3-5 seconds. At first I thought it might be the battery cuz the light that highlights what im in, like park, drive nuetral etc, never turns off. So if I dont drive it for days the battery dies completely. The battery is dead right now. But when I tried to jump it, it didnt even make any sound at all. And it wouldnt start. And as for where its leaking, there is this capsule lookin thing under the car. Im not exactly sure what it is. But it could be leaking from that or somewhere above it cuz the leak is coming from the top of it where I cannot see. I think there is some sorta hose attached to it though. So maybe that is whats causing the leak? And I think the car wont start cuz the battery. But how would I go about fixing the leak? Is there anyway to take off that capsule lookin thing. The best way I can describe it is that it looks like a big metal pill or something.