rlrl
As you can see the CP block is just to the side of the player entrance and dugouts in the North Stand.
I'd imagine the 'CP/3' reference means you'll be on row 3. I don't know whereabouts in that block seats 81-79 are but I wouldn't worry as the blocks aren't that big so you won't be too much away to one side and there's no pillars or anything to obstruct your view in the Paddock.