Do a search on this site, there are a few threads describing where and how to install. Google it if you have to. When I installed it last time it came with all the maps, no need to install other packages. When it first runs it defaults to the original second edition map, select new map should present you with dozens of maps/games.
My 87 year old Dad, a WW2 veteran still plays using the OOB rules(corrected). He would very much enjoy an OOB rules version of Triple A for when we all can’t get together for a f-t-f game. And to practice, too I presume.