A ssk is slip 2 sts separately as if to knit then put the L needle into the front of them and wrap the yarn around the R needle to knit together. It's in the decreases page with a video.
Salmonmac wasn't reading it as a dec so for her there were 4 incs (the YOs) and only 3 decs, but since it's a dec too, they balance out which leaves your stitches the same number. That makes the stitch repeat use 10 sts and leaves 10 when you've done the repeat. You might be unfamiliar with the double dec - s1 k2tog psso. For that you slip 1 st, k2tog, then pass the slip st over.
She also said to leave out the K3 but you need that in there. You'll k1 at the beg of the row, then do everything in the repeat across the row, but at the end you'll only have enough sts to k2 instead of k3.
Also take a look at the purl videos. You might be wrapping them 'backwards' which twists them and makes them hard to knit into on the next row. That's okay, but you might substitute k2tog tbl for the ssk instead and they won't be so tight.