I'd do stuff for myself and some stuff for the world.
For myself, I would: 1. Go back to colonial times and see what it was like 2. Go to California on July 17, 1955 and watch them open Disneyland 3. Go to different eras in Disney World and see what they were like. 4. Go find my mom when she was a teenager 5. Same deal with Dad 6. Go find my great grandmother after she eloped with my great grandfather and meet my great grandfather
And for the world, I would: 1. Warn them about 9-11 2. Bring Walt Disney to the future for cancer treatment 3. If not bring him back, stop him from ever smoking
I used to think about this all the time, there's one point in my life I wish I could go back and change but then... I wouldn't had become who I am if it didn't happen...which is in a way sad, but also good, so I would basically just travel back in time to different times in history. :)