Godlorica

That would depend on what abilities you assume being God comes with. If time travel is involved, "First" or "for a day" would be meaningless. Or the answer would have to be create the universe, because nothing could occur earlier than that.
 

I'd switch the salt and pepper shakers-- make the one with the little hole be for salt and the one with three big holes be for pepper. I use more pepper than salt. Or, since I am God, I guess I could just command myself to like salt more.
 

Suicide.
 

Why would I bother? Being God would be so far removed from humanity that there would be no point. It would be like trying to change the world for an amoeba.
 

End suffering.
 

God doesn't act he wills.
 

I would have to make things like stupidity excrusiatingly painful
so the aflicted would be easily spotted and avoided.