If I understand this, you want to remove your overhead garage door and replace it with two hinged doors. And you want to use plywood as a base for the doors. Plywood alone will not make a good door. It will warp all up and will soon start to delaminate. What you need to look at is more like a barn door, which is made from a frame with diagonal bracing that is then covered with some tongue and groove siding. It is possible to frame a window opening in a door like that. The other thing you'll need to consider is whether you have sufficient framing in the garage walls to carry the hinged weight of the doors.