K1, p1 trouble!

I’m trying to make mittens and I am having the worst time making the stupid rim! The pattern is…
K1, P1 rib for 2.5”- 3”, depending on how long you want cuff to be.
It says to cast on 20 stitches, I did that and whenever I get done with the first row, all my threads are crossed on my needles! I have 7 7 and 6 stitches on the three needles. Does anyone have any idea what the heck is going on!?
Thank you for your time!

Yep, when you move the yarn front and back to make the sts, you should be taking it [I]between[/I] the needles, not over the top.

thank you so much!