First, I would extend my power for longer than a week. I'm God right? Next, I would advance human scientific discoveries. Space travel. I wouldn't give it to them just enlighten a few to spread the knowledge. I wouldn't change the past, even though I want to, because I don't want to cause my existence to disappear on some Back to Future shyt because I changed the past. I would however bring a few key individuals back from the dead to speak for me as my chosen ones.
Wrath week. I would end all the fukkery in the world for two straight days. Murderers would be set on neverending hellfire (this special fire won't spread to anything else either...it just will burn those who are wrong. No forest fires.)....and I wouldn't allow them to die. Pedophiles get the same shyt. There would be a lot of mothafukkas on fire for two days. Then I will send down word if you worship me I will give you the ability to fly. You can keep your religion if you want, but if you come to my side, you will be able to fly.
Then of course I would expand the galaxy and create other civilizations and come and check in on Earth every two years.