Need Help Editing Product Images for My Website Using Photoshop

I'm a working professional product photographer and what @D Fosse wrote is spot on. You cannot fix bad originals.

I've been using Photoshop since version 2.5 in about 1994 and I CAN, sometimes, improve poorly shot images but its a big time sink. Get a proper setup with a light tent and diffused light sources. Look into a light table (frosted plexiglas that is lit from below) to get the white background.

Hello, just use remove background in the last update of Photoshop and you're done 😉 It's a real improvement  and a time saver.
After you can do an action to record all the steps you need and apply to other image. Do you know actions ? Do you nedd more help ?

You can also try the new feature in Photoshop beta called Harmonize.

It is a common misconception that this is just done in Photoshop. If you want a good result, it is done when photographing the objects.

You can mask out the object in Photoshop using any of the standard selection tools - of which there's a multitude depending on the particular requirements - but Photoshop cannot fix bad lighting. The lighting is what separates a good and "inviting" image from a bad image, regardless of background.

The ads and commercials you see are generally done by highly skilled photographers. But even so, a little consideration and planning gets you a long way. The most important thing is that you need diffused light, not a light bulb or overhead spots or anything like that. The simplest way to get diffused light is to bounce a camera flash off a white surface (ceiling or walls). You can also use translucent white plastic sheets or even fabric. Professionals usually do it with large soft-boxes attached to studio flash units.

This is straight out of the camera, no masking whatsoever: