What’s a good editor for a few photos?

That reflection is the one I’d deal with carefully, because a quick blur or clone job can make the background look stranger than the original photo. Once you’re already touching up several images, having layers and proper selection tools makes the work a lot less fiddly. You can use this Photoshop web editor here: https://fotoo.pics/en/edit_photo . For the set you described, I’d clean up the reflection first, then bring the darker shots closer to the rest so they don’t look like they came from different shoots. Finish with the crops and you’ve got a much more consistent set to hand over to the client.

For a few pictures, I wouldn’t turn it into a whole project with software installs and a dozen plugins. You just need something that lets you fix the obvious stuff, save the files, and move on with your day. Pixlr is worth checking out for that. It runs in the browser and gives you layers, selections, retouching, color adjustments, and enough control to clean up product shots properly.