Pullups and dips. Do them. Lots of them. Do the climb up motion itself. Many, many times. Jump if you have to. Jump less once you get stronger, until you don't have to jump. You can add weight to the pullups and dips if you want. If you want, you can do negatives of the climb up motion, too.
And there, my friend, is a comprehensive plan on how to achieve climb ups. Don't complicate it more than that.