Bad starter? Question

New guy here. Car has been sluggish to start the last few days than nothing but some whirring sound this morning. The battery seems low by seeing dim head lights, radio and circulation do work. Jumping it did nothing.

I think I located the starter under the battery. Is this where it is? I tapped it lightly where I could and it did barely start so I think this is where my problem is. By the way the head lights and interior lights did become brighter once it did start and now the service engine light is on.

Am I right in assuming its the starter?

Any tips on removing the starter or other info is appreciated.

the starter is actually located on the side of the engine block and bolted to the transmission. First thing I would do is find out what code your car is coming up with.