I'm a little late to the thread but I feel like things such as who you should train and what offense/defense to run clearly depend on your personnel so I feel like i'd be able to help you a lot more if you were able to inform me of the stats of the guys currently on your roster.
Without that information though, i'd say judging based upon the top salaries on your roster, your strength appears to be with your big men so look inside seems like it'd be a good idea.
Also, as far as trainees go, Israel, Fan, Samuele and Carmine all look like good options to train but who you train depends on what type of player you're looking to make. Honestly, at this early stage in the game, potential isn't a huge thing to consider in training as you probably just want to put the best team forward. At least starter potential, though a 6th man wouldn't even be too bad to train right now.