Thanks for your comments, Kathryn and Alice. Kathryn, I did the swatch and once I realised that all the plain squares on a right-side row had to be knitted and not purled, it all worked out fine. Really easy, actually! Oh, thanks to Carrie, too! I did look at the KAL again and there was a lot of info I didn't spot before.
I appreciate your response to my plea. Thanks, blogfriends. I can't believe I had to be such a drama queen. All I needed to do was try it out.