This steps through launching and also inserting some predefined worlds. I used these and have 4 planets in my creative universe. I can warp or portal between them.
F9 in test and creative will give you a menu where you can give yourself objects from the game in ANY COLOR. You select the amount (or SS) and the color. You will find the cheat skill loaf in the menu as well as other blocks from the game
I might be wrong since I have not been on creative in a few weeks, but I think you hit the F key to fly and then it is the same as walking or swimming for up and down and other directions. If you hit F while flying you will crash to the ground. .