New knitter - need pattern help please

I hope these aren’t too silly questions. I am working on an A-line purse. There are some things that confuse me in the body of the purse. Here are the instructions.

CO 24 st. This includes 22 stitches of the stitch pattern plus 2 selvedge sts used for seaming. You can k the first st and slip the last st of every row, k the first and last st of every row or use any other selvedge st you wish.
Begin working pat.
Keeping to pat, inc 1 st at each end every 8th row 4 times (32 sts).
Cont in pat as established until piece measures 11.5" total.
Keeping to pat, dec 1 st at each end every 8th row 4 times (24 sts).
Work even for another 8 rows. Mark each side of row.

My questions- Continue in pat in until piece measures 11.5 total - Is that length wise? width wise? both?
also - at the end of the body when I mark each side of rows. Is that for all 8 rows?
Thanks so much for your help :smiley:

No questions are too silly.

11.5 in in length

Only mark the one row–you’re probably using that as a reference later on for sewing or something.