Help with shaping arms and sleeves!

Hi there! I am new here and desperate for some help with this part of my pattern for a cardigan. In particular the k2, ssk sequence and the shaping of the shoulders. Could anyone try and help me understand please! I’m a beginner so quite inexperienced with patterns. Thank you

The ssk and the k2tog are both decreases. The reason for the different instruction is just so they are mirrored and look symetrical. The pattern is asking you to place the decrease 2 stitches away from the edge. So k2, ssk, at the beginning of the row then work across in the same pattern you’ve been using until you have 4 stitches remaining on the left needle, then k2tog and k2 to end the row.

The following for shape shoulder is a series of casting off stitches at the beginning of rows. Which size are you making as this would help us to explain more clearly?
What is the name of the pattern?