Day 7 - TACKLING DEPTH OF FIELD... I feel like I made some progress here!
I can see the difference!
Low number (F1.8) = wide aperture = SHALLOW depth of field. The front toy (which I was focusing on) is clear, those behind are progressively more blurry.
High number (F22) = small aperture = WIDE depth of field. The front toy (still focusing on) is clear, but so are the toys, computer and some of my livingroom/kitchen!