Casting on Knit & purl

Directions for a new project say to cast on with a knit and a purl stitch; can anyone direct me to a simple (and I mean simple) explanation on how to do this? I am really challenged by this!

I know of one where you do the cable CO but alternate btwn working a K st and a P st (by coming thru from the back side btwn the sts). There’s a vid for cable CO that would give the K st. Just incorporate the Ps.