Just about one month ago, my Pontiac wouldn’t start. It would try and try but couldn’t catch. The shop changed the fuel pump and filter. It seemed to be great after that! Today, it wouldn’t start on me again. I kept trying and eventually (while trying to switch work shifts in the process) it caught, but barely I feel. At some points the sound while I was trying went from a normal trying-to-turn-over-sound to a metal-on-metal sound. I have a year warranty on the pump, but it was brand new, so it must be something else? Thanks for any advice 
I hope I was descriptive enough, I don’t know much about cars!
After the engine started, did it run and drive normally?
Next time you get in the car, don’t start it right away. Turn the key to the “run” position, with dash lights on, but don’t crank the engine. Wait a few seconds, then crank the engine and see if it starts. Waiting a few seconds allows the fuel pump to build up pressure. See if that helps.
The starter may be failing.
The metal-on-metal sound you heard may be the starter drive gear grinding against the teeth on the fex plate.
If this is what’s happening, you don’t want to continue this for too long. Otherwise the transmission will have to be removed in order to replace the damaged flex plate.
Tester