Tick anything you already have, in any order. Quests unlock once this is done.
Your phone is a real camera and every principle transfers. If you do buy, a secondhand body with one prime lens beats a new body with a kit zoom.
2 things left above. Quests are real things you go and do, so they only make sense once you have what you need.
First one waiting: Shoot the same scene three ways using the triangle deliberately