Hey Boston! Glad you're jumping right in.
I think there's something weird with photos taken with cellphones. The software on the computer basically looks at it and goes "Oh, I need to rotate this so it looks right" but it doesn't actually permanently change the photo orientation - so anything that does't know about the orientation just displays it as is.
A member here recently said if you use your phone to just crop the photo slightly, it'll change the orientation permanently. Never tried it though.
(I think kitty is giving a bit of side-eye anyways.
Welcome to the forums, Pumpkie0!