I would train him at one on one guards and pick up a bunch of other prospects (good potential 19 year olds) and then just train away. Right now you can probably still find cheap superstar potential players on the TL at age 19. I would pick up 4 more guys to train with him (spend less than 10,000 on each). I would hire a lvl 4 trainer.
Read my guide on BBEconomics. It will help you.
Based on the teams that are in your league, you could go for a title this season if you wanted to. I would start looking for 32+ vets right away.
Play TIE until you have a roster. Unfortunately you have already lost two games so you will need to add to your roster soon if you want to run for a title. However, you can't afford to lose more than 1 more game before you start winning. Its always better to advance out of Div5 if you have a good chance to. Luckily your Div does not look that challenging.
Manage your gameshape and play TIE while adding vets.
It will be a challenge, since you already spent a bunch of cash on the arena, but it will be fun
