Firstly I'd visit a doctor to make sure I wasn't tripping balls, if that checked out I'd do something big, but ineffectual to make sure he told the truth, like giving Mercury a moon or something (Probably a bad idea to go straight to stopping volcanoes on my first go). If that worked, I'd build an island in the middle of one of the oceans somewhere to be my headquarters.
After that's settled I'd move onto the big problems, climate change, world hunger, all the sickness we've got going on, the dick shrivelling amount of debt everyone is in, and so one and so forth.
After all the big stuff is solved with sustainable solutions and assuming I didn't just snap and kill everyone I'd live on my island, and begin experimenting. Along with seeing just how far godhood goes, I'd make regular trips around the planet appearing before crowds and such to make sure people know I exist, to keep the intentions of my commandments (if I have any) as clear as possible, and to personally issue any nessesary revisions to any holy texts people have written about me.