What to do? Needing to troubleshoot.

I just got 2004 nissan sentra standard driven it has
been setting up for about year now. Before buying
it I was told at the time only thing that could be
wrong with it was the cam shaft position sensor, or
catalytic converter causing it to lose acceleration
power.  So interested in the car and wanting to see
if would run I put a battery pack on it jumped it and
it fired right off. It Idoled well but when giving it gas
(reving the engine it seemed to cut out and lose
power) well moving on, I then cranked the car to let
it warm up a bit to drive it home so i stepped away
from the vehicle while it was running for a bit only
to come out and see white smoke coming from
engine compartment. I immediately killed the car
noticed the temp gauge was reading hot. And then
I went back on front to inspect the engine the
plastic on top the radiator just exploded. What
causes that? And what should I do for
troubleshooting after I replace the radiator
tomorrow...