Trainings/bonuses & players condition importance!!!

[Maxxy77]

I am lvl 40 as a manager,and my club is 32.....so i don't have free agents..

[Ποσιδονας]

I am lvl 40 as a manager,and my club is 32.....so i don't have free agents..

those 3* old players we see in the market from time to time, from where they're coming ?
Is it when a team has a player who is going to retired and we release him to have an extra position ?
Are they created from the game ? like the nordgen ?
Why in higher levels there aren't players like them ?