I would raise a space armada stretching throughout the galaxy, creating technology that benefits anyone who wants the tech along the way. Then I would explore other galaxies, just for the hell of it. If I find any oppressive galactic empires like in cliche sci-fi movies, I'd destroy them but leave a few high ranking officials alive to remind them of their destruction and how little of them are left. Rinse and repeat for that galaxy. Continue until I get bored and go do something else.

Like become the Chosen Undead.