your alternator is putting out?  You should see 14 something volts dc
at your battery terminals IF your alternator is working correctly.

This is the first thing you check, before going off on a wild goose
chase.

Lg

" When I go to start my car, sometimes it will turn on, then the rpms
will go down, until eventually the car turns off, it will do this over
and over, and usually if i give it a little gas it will be fine.. at
least every time I have it seems to work just great.
It doesnt happen all the time, so Im not sure what it could be. My
guess would be either the fuel pump or spark plugs... any other
suggestions or ideas? is there a way I can check it myself? Thanks in
advance "

Is it misfiring? Based on what you have written here it sounds like a
fuel delivery problem, which would not be affected by changing the
spark plugs. Could be a fuel-pump relay that is not latching to the on
position after the engine starts. Usually the ECM will command the fuel
pump relay on when the ignition switch is in the start position and
then rely on getting a signal from some other sensor to keep the pump
on. If it shuts off the car may run for a few seconds and then lose
power and gradually shut down.

Chris