Recommend reading Duane Cole's book, 'Roll Around a Point'. Only after you've memorized it, advance to Neil Williams', 'Aerobatics'. Neil fills some stuff in, since Duane's book is for absolute beginners. picked up keeping the power in on the down side of loops and hamerheads, from Neil's book, to keep the energy state up, and using g to control speed.
When you have that knowledge floating around in your head, the instructor will line it all up for you. You'll progress faster and get more for your money. Stay away from the sym for this, aerobatics are tactile; control forces and response, wind and engine noise, g forces, the smell of oil dumping out the breather, the feel of the skin moving on your face, loss of peripheral vision and color sense under heavy g onset rate, on....and on.
Good luck and Have Fun.