Telekinesis. I would train my aura and spirit to unlock more and more telekinetic abilities, Until I unlock meta logic manipulation/metapotence. I would use that power to build my own nation, and move people who are oppressed or suffering there. :))))

I would probably want as of now a photonucleic body (a kryptonian body) and train to get better at fighting then go into a sun and absorb all the energy for thousands or even millions of years depending how powerful i want to get at that time, I could also maybe train my body to absorb the sun's energy more quickly to get more powerful quickly, with this I would have all of supermans powers hopefully ?, as of the kryptonite weakness I could probably build a resistance to it, or I could train my body to not absorb the energy given off of the kryptonite.

So basically you want to be superman prime one million? :)