tired from training
More like injured from training!!!!! is this the first lot of injuries of these players? If it happens often to the same player, then he is injury prone. Dump him asap.
Did you buy young players (future potential if not injured often) or mid (realized potential) or older players (experienced).
On formation, like the earlier poster mentioned, players, especially defenders and wingers, should be able to play in more than one position.
Also if you accumulate your skill points for +-two days you should see which players are improving and which are not. Also watch for players who don't recover within 20 hours after training/playing.
If you are putting tokens in, then its not just the formation but your investment in the squad. DONT ( I think) put your tokens in improving club facilities.
Finally don't rush into trying to go undefeated or not conceding goals. That will come later...for now experiment with the formations, players and do a little background check (swot) on the opposition ( good / bad players, weak spots, etc)
..out of breath..ENJOY
and expect to lose... BUT not in your case your squad is too strong for L1 and 2 and 3...so go ahead and experiment