You have to give it bones.
Chat with our AI personalities
By taming a wolf. Wolf taming can be done by right clicking a wild, non-hostile wolf with bones. Give bones to the wolf until heart particles pops out of the wolf, then it will be yours.
No
Not in the current Vanilla (Minecraft without Mods) Minecraft, no. But their are a few Mods out there that will make that possible.
feed them raw fish
In Creative mode you have everything in your inventory,search by clicking the compass tab at the top-right