Shortly after waking up in the yard you will find your first tent for analyzing resources. The easy first items for analyzing are:
Pebblet
Plant Fiber
Sprig
Sap
Grass Plank - This triggered the achievement for me
It appears that interacting with or passing near other items triggers the achievement. My list of Natural Resources (both analyzed and unanalyzed) is only 14 items long and includes:
Weed Stem, Acorn Shell, Ant Part, Dry Grass Chunk, Thistle Needle, Clover Leaf, Grub Hide, Mushroom, Aphid Honeydew.
I believe that the items you learn as "ideas" when you interact with items count toward this at the time of this writing.