room dimensions

I'm going to build a multi purpose studio on 5 acres in a location where there is little outside noise to be overly concerned about. I'm in the country, on a very private lake where the sound of nature is actually something I would rather hear as a natural ambience (maybe I am onto something...

I just moved into a house where I would really like to be able to mix. I have 7 24x24 acoustic foam tiles. I know ill need other treatments. See the picture for my room dimensions. I'm not sure what else I need, or where to place what. I would like to be able to record in the room as well… if...