Started this Morning, then no success less than an hour later.

Hi, I am not super mechanically inclined so I'll try my best to describe. Recently, the truck has been taking longer time to start, usually a couple seconds of cranking. After parking it after a short drive this morning, I got a gravely sound coming from the front passenger engine, and that has only happened a couple times. Since, I get no crank, but a whirring sound from what seems to be the bottom of the vehicle.

In the attatched image, I have circled a part of the vehicle, I could not find online what it was, that was another source of a gravely sound while trying to start sometimes. I think it's the starter finally going out, I am looking for someone who has more experience with this share their thoughts on what this could be, apologies if I didn't explain well.