Here is the easiest way to make those first HST's for the black and white; our Orca assignment for the week.
Let's see, can I attach a photo? It is more difficult than in the past, but I can't learn without trying.
step 1: 3 1/4" square. Sew diagonal, 1/4 " away from center mark
step 2: Cut between sewing, diagonal
step3: Cut THAT triangle into half, across the sewing line
step 4: open up, press,
step 5: sew those cute little pieces into a block, which will be 2" square finished size.