Would shapeshift into a person and live out hundreds of thousands of different lives among my creations, mostly being famous warriors or great legendary mages, so that after a few thousand years, I would purchase a history book, turn into an old man and go around pointing out certain legendary people long gone to random people on the street and say, "I was that guy. I was him too. Oh you remember when he did that? Yeah that was me!! Impressed?". I would probably sound crazy to passerby's...but at least it would be true.
I mean, whats the point of creating humanity if you aren't going to live among them? I would make myself appear to age and die as they do, but I would simply just shapeshift into a different human form, and randomly appear in some other town pretending to be a wanderer and would then strike up a new entire life. As for getting married and having children.....since I'm the creator, I would have to make sure any offspring didn't become stupendously powerful, so I would alter their genes to make them grow up to be powerful in comparison to other humans.....but no demi-god-like stuff like going around and cutting skyscrapers down and shit like that.
Basically, I would sandbox the hell out of my own world. Considering my love of history, this is like a dream of mine. A wish. Likely my greatest. Doing something like this, and then being able to get a history book and read details, laugh about what was recorded incorrectly, and also feel pride when I see the names of past lives I lived, and be amused, annoyed, or happy at how I was recorded.
Hopefully, it for some reason this wish happened to actually come true...I wonder if I would get to create the geography of the world? Like shape the continents, how many of them, the size, as well as how large the planet itself is? Interesting thread this.
I also wouldn't invent much beyond what I consider necessary, and let my human creations do most of the inventing and progressing the world's technological/magical level. Though I would definitely prevent any "nuke" like magics from being formed. Can't let my creations destroy my....well....my creations.