Pattern asks for cast on in the middle?

I am trying to make a bath mit and I am trying to follow a pattern. I have knitted 30 rows already that started with 36 stitches and has now been increased to 48. The next step in the pattern says…

“K29 TURN Cast on 1 st K14 (including st on needle after cast on)”

I am a little confused. First, how do I “cast on”, and is this on the right or left needle?

Please help

Just do a backward loop cast on ( it might be easier to do it on the right needle, but then you want to move it to the left so you can knit it and count it as one of your 14 sts. I’m suprised to see CO1…usually when increasing 1 st you could just M1…maybe it causes a different look or shape though.