You have 2 colors - MC, the Main Color and C (or CC) the Contrast color. Cast on with the MC and p a row, k a row 2 times, that's 4 rows. Then start the C and p a row and I think you also purl the next row instead of knit it. A turning row shows as purl on the knit side where you turn up for a hem.
Then go back the MC and p a row, k a row twice, then p another row (5 rows with MC). I think the joining row is where you turn up the hem and join the sts with the cast on sts, knit them together - the next st with the first st of the CO, etc. Then purl another row, and start the chart at row 17. Then when reach the 9th row after joining, inc a st on each end of the row and do this every 8th row after that for 9 times, then every 10th row 2 times and you end up with 71 sts.
It refers to 'as for back'. Did you do that yet? There might be an explanation for the turning and joining rows in those instructions that might be different from how I interpret them.
sue- knitting heretic