Give your worst player £999 million wages. Now spend all your funds and then release that player. Now you will have extra money.
When a player gets sent off, go on to offer new contract and put £35,000 a week. With that he will never get sent off again for the rest off the season.
To get and train a good 16 year old, go to player search and choose the age range to 16. Choose all divisions except the one you are in. Choose all the players that are loan listed and you will come up with a load of 16 year olds that are loan listed. Choose the best one and loan him out. Let him finish his first training, e.g Passing and then buy him. ( it will say for example, liver wish to aquire the 16 year old from liverpool) When you buy him set his price up to 23m and put him as a sub. Continue with his traing and it will be useful to write down quickly his order of training as he will get demoriaised and will take longer to complete his training. If you do this right he should only take 2 weeks to complete his training. Give him chances to play on the pitch as it gets his value up and will improve his stats on how good he is. But you should notice before that players can only improve up to 3 on every time you train him. But by doing this he will improve between 3 and 8 every time. Make sure you dont repeat the same training over again as he will become demorialised and will become unhappy. The happier a player is the more he will improve. As he gets better his value will increase and by that time start to rise the amount you want for him. As he gets better, give him more chances to play on the pitch as he will keep improving also on the pitch. When he scores goals his passing, heading and shooting will go up every month. It will be handy to write down his order of training and stick to it. If you do all of this, and you train him for about 5 to 9 years you will start to get big bids for him and he will turn into a key player. Or of cause you could just keep the player and continue training him up. ( value of defenders do not rise but will improve a lot still if he is loaned and then bought).