Train Dávid Rudas he looks like a good trainee. If you posted his skills I could give you a better idea of how to train him. You have 2 other 18 year olds that you could put as his back ups for training. If I were you I would play them all at the PG position so you can 1 position train.
Other then that since you should be training at the guard position you should buy a good big man inside to carry your offense while your trainees develop. Look for someone something like this.
Jump Shot: average Jump Range: mediocre
Outside Def.: mediocre Handling: inept
Driving: inept Passing: average
Inside Shot: prolific Inside Def: proficient
Rebounding: proficient Shot Blocking: average
Thats a pretty good power forward for div V and could be a quality starter for div IV if you got a player like this but with prominent/prolific inside defense.
It probably cost about 100,000 to 200,000 for a player like this.
Post David Rudas skills so I can give you advice on how to train him.