To inc 2 in the next stitch, you can knit, purl, knit into the next stitch. So you're turning one st into three. If you just knit into the front and back, you'll increase one stitch.
So you cast on 4
Then your first st gets increased to 3, plus the other three makes 6.
Next row, and every row after that you're increasing one with the yo at the beginning of each row.
Your pic looks like it's coming out correctly.
I edited this because, well, I goofed and brendajos set me straightt. Kudos to her.