Help decipher what I should be doing next

I am knitting this:

I have reached the part of the pattern that says:

Cast on 3 sts at the beginning of the next row, for armhole shaping.
Next row: P to last 4 sts, k2, kfb, k1.
Continue increasing at front edge every row but without the garter stitch border at armhole edge, until you have 48 (54, 60) sts.
Purl 1 row.

I’m lost at what I should be doing next. Any ideas? I’m really stumped and don’t want to continue to have to frog because I misread.