"That I understand but then the patterns says:
Row 1: K1, P1, K1
Row 2: K1, work K1, P1, K1 in next st, K1
Row 3: Seed St across
Row 4..."
The directions in row 2 are really an increase. You have 3 sts at the end of row 1 and at the end of row 2 you'll have 5sts. You're to increase by working 3sts into that second st. Do that by starting out to knit as usual but don't drop the knit st off the left needle. Bring the yarn around to the front between the needles and begin the purl into the same st but again, don't drop the st off the left needle. Finally, bring the yarn to the back between the needles, knit into the same st on the left needle and now drop it off the left needle. You'll have 3st on the right needle in place of that one.
This
video may help although it's p1k1p1 into one st.