ok. let's see if I can break this down. a YO is only a piece of yarn that is looped around the needle once. it's an increase that leaves a hole. On the row after a YO, when you come to the yo, it will look like yarn draped over the needle. if you're doing stockinette lace, you would just purl into the top of that loop and slide the loop off of the needle. for example, if you're beginning a piece of stockinette lace, let's say you cast on 10 stitches and on row one you K5, YO, K5. after completing row 1, you would have 11 stitches on the needle. on row 2, you would just purl each of the 11 stitches.
You're a great friend, but if Zombies chase us, I'm tripping you