Ok, your money.

Buy abilities like Freekick taker, corner taker, defensive wall, defensive header.

Best GK ability is one on one stopper.

Make sure the players you sign end in 4 or 9 quality so you can get more use out of them next season.

Try to sign under 25. My experience is scouts don't train fast so it doesn't really matter but having an oldie has no sell on value.

The formation is upto you.

If you want to be adventurous, try 4-2-3w-1 it's quite popular lately.