Read and digest the book "Winner's File", by the late Henry Kuck. You can buy a used hardback copy in very good condition from Amazon for about $4. After that, read the book "Blinkers Off", by the late Cary Fotias. A used copy in very good condition of this book will run you about $6 on Amazon. Continue by opening a modest account at Twinspires so you can access the day's past performances for the cost of a daily minimum bet. From then on, handicap the races and place minimum-sized bets so you can pay the cheapest tuition possible for your racetrack education.
Forget about "paper-betting", by the way. Mind bets do more harm than good, IMO. When you bet on paper instead of putting out real money, you end up with the impression that you are a lot more creative and a lot more courageous than you really are. This can be very dangerous to the bankroll...and to the psyche. You can't learn how to swim without jumping into a swimming pool...and you can't learn how to bet the horses without jumping into a wagering pool.
Thus spoke thaskalos.
