Have 11 players to warrant your preferred kind of line up (3-4-3, 3-5-2 etc.) with a passable minimum level in the primary skill of the post they must ensure.
In this composition the players on the trained line will be young and often inexperienced (19 years old at most). The other will be relatively old (25-30 years) with experience (weak-inadequate minimum preference) to be efficient.
You'll have the trained lined doubled, these "duplicates" will train by playing friendly matches.
The players passable or better in a primary skill (only keeper, defending, playmaking, winger, or scoring). You'll usualy get one guy of solid level in one of these skills and a pair of passables ones.
then in order of priority: inadequate, weak, etc.
You won't keep more than 24 players at any time. You will fire the worst at same time you'll recruit some new ones.
No need to dream you won't buy any star. On your 300k€ at start there are no more than 230k€ with the purchase of the coach. Put around 130-150k€ in your young trainies and 100k€ in the old ones of the other lines. Anticipate and hold on your budget !
This is the top priority ! Profile pattern :
Try to get 2-3 young players a bit better than the others if average level is quite low (either secondary or primary, both at the same time is rarely possible).
Only after the young trainies are bought ! Profile pattern :