By the end of the season with 1 position training I think you can reach these skills:
Jump Shot: 8 Jump Range: 7
Outside Def.: 7>>8 Handling: 5>>10
Driving: 3>>8 Passing: 7>>8
Inside Shot: 7 Inside Def.: 5
Rebounding: 2 Shot Blocking: 7
Train handling until he gets to 10, then train passing to 8. There are 11 full weeks till the end and I think he can easily get there. You don't need to train driving cause it will train along side handling and passing at the end. Hopefully OD will pop too from handling training. If you manage to train like that, he'll be really good at PG where you use him. Estimated salary around ~7500 $.
After this season I recommend you get rid of him and make some bucks because he'll reach his potential soon after this training due to his low potential (starter). Ask around 500k. Then buy another trainee with at least allstar potential or use one of your new rookies if he's any good.