Yes, the pattern stitch is the K3, p1 repeat. It’s offset on row 2. It should look like this if I’m seeing the photo of the cardigan correctly.
There should be a column of Vs on right side and wrong side. Is that what you see on the back and left front?
When you worked the K1P1 and then the k3p1 to the end, did you start the row with a k2tog?
Row 2 k 2tog k1,p1, *k3, p1 to last 3 sts. k3