Are all the Pictures from Pixabay & Unsplash Free for Commercial Use?
Yes, most of them are.
You can click on the license tab on either one to fully understand the agreement.
Just selext Pixabay or Unsplash and on the top right you will see "Pixabay License" or "Unsplash License", click either and the details are in there.
Some common sense has to be applied though, you may see a Disney charactor or Marvel charactors, or things like that, that Pixabay or Unsplash have not noticed in their database yet. You can not use things like this. So again, please keep this in mind and use common sense!