I know it's a really basic thing, but I'm new to creating pages, I've only created two, and all the tasks are at 9/however many there are, I can't remember.
Just be patience, you will probably get answered within a few hours, no need to go to someone's wall.
There are various ways to add an image to a gallery. Usually there is an "Add" button on the gallery itself. Would you want to give a link to the page in question so we can look?
I figured it out, but thank you for trying to help! I discovered there was a "add photo to gallery" button under the gallery of my page :>
What do you think?