It is far too cold for humans to live on Neptune, so you would need something that could keep you warm. You would also need food, water, first aid (something similar) and something to do so you wouldn't die of boredom!
Something to keep you warm food, water, and oxygen that's all I can think of.
you will need food, water, oxygen tanks
I think you would need a space shuttle to get there and stuff to keep you warm and food and water.