the reg CCA wolmanized treated lumber? If so, as you have found out, it is oozing with chemicals. One whack with a hammer or over screwing a screw will cause liquids to ooze out.
You must let this completely dry out before any paint will even consider to stick. when the liquids leach out the paint will bubble and peel off. So, with winter around, no drying will take place this year. I would consider this a spring time project to paint it. CCA wood does not need painting, but it only enhances the looks with paint on it when used other than a deck. Remember this: paint only enhances the appearance. it does nothing for duration, the process has already taken care of that.
One note, on the joints or seams of the plywood where butted up to another. It would be a good idea to install a runner down the seams and screw this to the two butted joints, will stop that ply wood curling of the laminates. always use screws, the galv or elect plated ones.