The tutorial world has bones in a chest sitting near the farm where all the animals are located in pens. If you are on creative, you can grab some bones from the creative inventory. The amount of bones needed varies. Each bone has a 1/3 chance of taming the wolf, so 6-9 bones should get the job done.
If you are in Creative mode, you can get a wolf spawn egg from the creative inventory.
Don’t click on the wolf in Minecraft PE, as it will turn hostile and attack. Instead, press the Tame button. You will not be able to tame a wolf that you have attacked.
Click the wolf to make it stand. Then it will follow you around.
If you don’t want it to follow you, you can click on it (left click or the button you used to tame it) to make it sit, where it will stay until you let it up.
Naming a dog Dinnerbone will make it upside down. Don’t worry! This won’t affect the gameplay, it’s just an easter egg.