Cadillac won't start!!!!

I tried turning on my car but it won't turn on at all.
It doesn't make a sound at all while turning. All the
lights and sounds turn on. One day it'll turn on
perfectly find... Drive it for a day then the next day it
won't start at all. I had a friend hit the starter and it
crank up but the next day same prob. I took it to get
it diagnose and they told me something about the
throttle actuator and something else. I'm a bit
confused. I know it needs to be fixed but I want to
at least keep my car running until then! Where do I
start?!!