I’m confused

Hi, I’m quite new to knitting and I’m a tad confused.
The pattern is for a hot water bottle cover and appears to be rib as it’s k1 p1 repeated every row. It then says to finish on the wrong side. How do I tell which is the wrong side?

I may be wrong but I don’t think it really matters since there is no wrong side. And the pattern doesn’t designate if your first row is a WS row or a RS row. But assuming the first row is RS, that means the WS row will have the tail from your cast on on the opposite side as your working yarn.

Does that make sense?

Yes that makes perfect sense, thank you x