No insulation or vapor barrier

[Troy Welch]

I just bought my 1st investment property. It is a 50+ year old property that is in pretty good condition. I just ripped out the kitchen cabinets and have a couple of concerns. 1. There is no insulation in the exterior wall. There does not appear to be a vapor barrier. The house has vinyl siding attached to plywood (I doubt it is treated). 2. The foundation under the cabinets appears to be damp. Since the walls are open and cabinets are out what should I do? I was thinking: 1. line the wall cavities with 6mil plastic and roll insulation. 2. Lay 6mil plastic under OSB (to match exist laminate floor thickness) and set the base cabinets on top.