Easy platform for a small metal frame pool
Sand bags would be a good idea. I normally use railroad ties drive a piece of rebar through the tie into the ground and fill the area with beach sand (I live close to the ocean and sand is free). I would put a tarp down over the asphalt and the filled in area so it won’t wash out , I haven’t used plywood just a tarp it helped to extend the life of the liner. Some 25 years ago I used to take temp pools down but now I don’t a week and a half of vacuuming leaves out and the kids are in it in May even in Oregon they are nuts!