Help with instructions please

I’m a beginner and I’m trying a sweater… SO confusing! I’m finished the cuff but now it says "[B]inc rnd[B] M1L, knit to last st, M1R, k1–2sts inc’d. Rep inc rnd every 8th rnd 9 more times, then every 6th rnd 1 time --58 sts

So I start my first stitch with an m1l then knit until I’m at the last stitch before my marker then do an m1r then knit the final stitch? And then I just do a St st for 8 rnds then do the inc rnd, then I keep repeating that 9 times. I think that’s what it means but I don’t get every 6th rnd 1 time --58sts?

Welcome to KnittingHelp!
You’re right about the placement of the increases but if you start with the increases on round 1, then you want to knit 7 more rounds (so that’s 8 total rounds) and increase on the next round, a round 1. Repeat those 8 rounds 9 times more. Then knit 5 rounds and increase on the next round.