Is it the selvedge stitch that is the problem? The pattern has an extra stitch at each side, a selvedge stitch which will be used for the seam. You'll begin and end each row with a k1. For the ribbing:
k1, (k3, p3)4 times, k3, k1.
When the ribbing is long enough, end having completed a right side row (RS), change to the larger needles, purl a row, increasing 10 sts across the row.
Knit the next row as follows: K 1 (edge st), * K2tog, yo *, repeat from * - *, finish with K 1 and K 1 (edge st).
From now on you continue in stockinette stitch, increasing each side of the center stitch.
If that doesn't help, let us know what specifically is the problem.