I normally have a full squad of 22 players, the reserves normally are 3* fast trainers close to the 4th star, that i have for backup for playing If my 1st options are injured, i train them every day and try to improve them the mutch i can, whend i find a better player i sell them, they are always a good investimento, because you always gain money with them.

Youth facility L0 take 28 days.
L3 take 24 days
L5 take 20 days and so on.
You receive 2 players one a free agent 2* and the other a 4* that will cost 15 to 24 tokens to sign.