If you post pictures that look normal on your phone or tablet, but after upload here seem to post upside down or sideways, the issue is likely that the images were taken on a mobile device that auto rotates content to always appear right side up. The forum software can't discern what the intended orientation was so it defaults to the actual orientation of the image (regardless of how your device auto rotated it to appear correctly in your local view)
Some options:
1. Always take the picture in portrait orientation or:
2. After taking picture hold your device upright and then edit the picture, resaving it with a new name.