There really is no "how to" book that comes from the game.
They have added a tutorial at the start of the game that new players can use if they wish that shows some of the basics.
However, most everyone just learned as they went on. Unfortunately for new players, this is not as easy b/c there are not that many other players in the start-up areas to ask advice.
As for your questions, you get a hunter pet by speccing in beastcraft. There is a level 1 spell called Hunter's companion, so you should have this even if you did not train at all in BC.
To add a friend to you list (lets say his name is Hunter-Ector), you would just type /friend Hunter-E when he is online.
You can type /help and get a list of topics to review, but we all felt helpless at the beginning of this game. Some people don't remember it and are too arrogant to help new players, but if you ask around, you will find someone willing to help you. Joining a guild can help also, although whenever I create a new toon, I see a lot of newb questions asked and answered in the starter guilds.