Hold your dominant hand fingers in a V shape and your off hand index (or whichever finger you prefer) up in the air and line them up like a rifle sight. Move your 'V' fingers up, and adjust your front finger until the sights are lined up again. Your index(barrel) went up to line up again.
If I were you I would do some reading on proper iron sight usage, sight picture, adjusting, etc. Watching some you tube videos if you can find quality ones may help as well. Once you know you are sighting it properly etc, then go back and try again.
Move the rear sight DOWN to lower your point of impact.
Good luck!
-Jake