Advice needed please!

I am knitting sleeves for the first time! My pattern is as follows but I am unsure what method to use to increase and how many stitches in to do the increase. Please could anyone help me?

You could use a M1 increase (picking up the bar between the edge stitch and the stitch next to the edge if you’d like.
A knit front and back will also work. After the first increase row, you could make the increases one stitch in from the edge.

Thank you so much. Your help is always really great.