Tick anything you already have, in any order. Quests unlock once this is done.
Tree protection is not politeness, it is what stops the webbing stripping bark and killing the tree, and it is why parks ban slacklining where people skip it.
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: Try a slackline at a park or a friend's setup