For salary there are nice calculators to give you an rough estimate:
(100218.2)i prefer the coach parrot for it, but also the very nice Buzzermanager give you a nice overview about the estimated salarys of your players.
What to do next it quite difficult, because he is on his first step of a very long road and could use training in every skill.
For your actual performance, i tend to train OD to 10 or 11 first, and for getting a very nice player i would train him out of position as much as you can(depends on your weekly schedule).
For the best result in training speed, a balanced or a driving/handling heavy player will be best. So there are still many possible ways you can continue to train your player, and it is nearly impossible to make a big error while training him so long you will train him.