To all veteran players; when is the best time to start the youth academy? And why :)

As soon as you have the resources, it’s worth upgrading straight away; that way, you’ll already be up to speed when you reach a higher level, rather than having to start upgrading only then.

As for the training centre’s level: this is limited by the level of your VF rating.

A level 8 centre is best suited for producing youth players.