Tick anything you already have, in any order. Quests unlock once this is done.
A block that is already colonised takes the hard sterile work out of it. You mist it and it fruits in a fortnight, which tells you whether you want the harder version.
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: Grow a mushroom kit