User Manual AmazonBasics NY1507-15K Air Conditioners

Yes, it can. We have a portable one all ready. We built a wood frame with treated wood for extra weather protection and painted it with good white paint.
Set it in the window away from the main entrance. Cut a hole and put in the plastic lead for air to go to the outside. Attached the hose and it was all good to go.
We caulked around the window with foam rubber strippimng to keep out the heat and cold weather. We also have one that has NO DRAIN to the outside.

I would not store it on its side, due to the fact that the system contains refrigerant which is in a liquid/gas state to work. Probably a specific area for it to collect when stored upright. It could be ok, but I wouldn't.

No it doesn’t use water. It’s an actual air conditioner.
If you run it in dry mode you will need to hook up a drain hose to drain the condensation.