First he is VERY cute!! and looks like he is having fun.
Be concerned about keeping him healthy and getting him socialized with many pupppy classes. This is what will mold him the most into the wonderfull adult dog you want.
i suggest a trainer thats routes are positive motivation.
What he looks like..first clue if the daddy was black he would be black as fawn is recessive to it. His head is very square at this time so his father must also have a blocky type head. longer nose possibly. Do you know what the other litter mates looked like??Was there any longer coats or really long legged babies??
To me I would say that he was a boxer crossed possibly with a bully mastive or the Staffarsire Terrier.
His daddy could have been a total mix of shephard, rottie, pitty and so on so who knows...
like I said train him with love and mold him into the best adult you know how.
:cool: