There are a couple really good threads stickied to the top of the Help Section:
https://www.quiltingboard.com/qb-help-center-f27/
My system is really locked down with virus blockers and such and I have a few other things going on, so some of the pictures didn't match what I saw.
For me the biggest problem was the file size. After I transfer my pictures from my camera to my computer, I use the camera software to rotate the pictures or crop them or other basic editing -- which is pretty much all that has.
Then I use this free but limited site to reduce the pictures, mostly because while limited it is easy and it doesn't set off my computer protections:
https://www.reduceimages.com/
There I save them to my downloads file. Once in downloads I can post them here, or then I typically transfer them to my "quilt" directory under photos and name them.
Edit/PS: Usually there is something like "share" on the phones I've seen. I don't see well enough to use a smartphone so not much help.