I'd make a sweet mansion in space, invite all my friends who are struggling in life. Fill it with secret passageways and magic items n stuff too. I'd retcon history to make me be seven feet tall, instead of 5'6". Probably travel back in time to several thousand years ago and make one random person immortal for the hell of it.

I mean, I wouldn't want to mess around with humanity too much. I wouldn't want to prove I exist, and I wouldn't want to ruin people's lives with my shenanigans. If anything, I'd create a miniature simulated world, where nobody in it is actually "real" that i can mess around with all I want without feeling bad. Like a sandbox.

Then I'd unleash all kinds of supernatural stuff on them to see how they react. Make people invisible or huge or tiny or create weird magical pocket dimensions full of magical items and monsters... ya know?

omg dick trees

Detachable boobs. So people can sleep on their stomach.

change the whole world into anime

from ears to see and eyes to hear from

No tax on chocolate!

I would strew dollars from sky.

I would turn every political leader's faces into that icon

Since instituting common sense is part of world peace, I would turn every car in the world into a Mustang GT.  XD

 Trees would grow meat, sculptured into the shape of the animal the meat would normally come from.

 Everyone would wear latex suits as clothing.

 Bartering would be the means of exchanging goods and services, with drugs as the currency standard.

 Zoo animals, such as tigers, would be sold at pet stores.

 Any desert space larger than ten miles, with no habitable buildings with that range, would be a free-for-all zone where psychopaths and contest “winners” would battle to the death.

I would create a chocolate river. Because why not.