All you have to do is play the tracks you've won recently twice or more and win them.
No. There is not any code.
No but you can get a lot of answers in the books in the Office that's all I know of at the moment.
After you care for it a couple of times. Then it grows up.
To do a pirouette while cantering draw a backwards C on the touch sceen. Later, when they just ask you to do a pirouette, draw a full circle on the touch screen.
All you have to do is go down the hill, away from the stable, make a right turn and enter the paddock. All of the hores you can ride are in there, including the foals. Hope this helps! :)