Thank you Razz, I'll try to follow your advices.

The only problem is that no one is buying a single player, probabily because everyone is at the end of the season.
The MC-age18-4*16 and the AMC,AMR-age19-4*16 train very fast. They are worth 1.2M and 800k, I'm selling them -20% but no one has been interested in two days.

Moreover, in season 1 we can get only 3*14 free agent players at most.

AAnyway thanks for all your advices, I'll try to follow you