I recommend doing the main Pet Battle quest chain
, if you haven't already.
Also, here's a handy general guide on Pet Battles
that might help.
While you're completing the PVE encounters/quests, start battling the wild pets around you and capturing any rare wild pets you come across.
Pets on your active pet team will begin earning experience and start leveling up as you complete both PVE and wild battling/collecting activities.
To reach a point where other guides you've mentioned become relevant, you need to first have a few pets at max level (25). There are 2 ways you can accomplish this: Unlock the Menagerie in a level 3 garrison in Draenor, and complete the quest that rewards a battlestone
that instantly levels one pet to 25. Or complete the activities I mentioned above.
Unfortunately you can't just buy level 25 pets and add them to your collection. You must first have a level 25 pet in your Pet Journal in order to learn other max level pets. Once you've leveled your own 25, you can buy other pets from the AH. If you don't want to wait and grind out the pet experience, that is.
As for the pet food and Safari Hat -- you don't absolutely need them, they just make the leveling process go faster. You can collect and battle without them, and you pretty much have to when first starting out in Pet Battles.
TLDR; Main goals in the very beginning (at least IMO):
- Complete the Pet Battle PVE quest chain as far as you can go (unlocks achievements that unlock more content/pets/items)
- Battle wild pets for experience
- Capture any rare quality wild pets you come across
- Get one pet or a few pets to level 25.
I suggest leveling up a mechanical pet, a beast pet, and a flying pet first since you'll most likely run into wild pets that those 3 families are strong against.