In your second photo the black plastic piece I see is one of the 2 side tanks on the radiator, on one of the side tanks there is a petcock/drain to drain the coolant from the radiator but it's not in your photos that I can see, all of the above are parts of the radiator, you just need to replace your radiator with a new one to correct the leaks in your photos, you can get a new Denso or Koyo radiator, both are of the highest quality and equal to OEM for about $100 plus the labor to install it.
I would as mentioned check the water pump as well, there is a small hole on the bottom of the shaft housing behind the cooling fan, that hole is where it would be leaking if it's bad,