To answer your question, you will need to buy a Colosseum which costs about 50,000 coins in dragonvale. Other than that I don't think there are any other contests to come yet.
An agonistarch is, in Ancient Greece, a person who trained people to compete in public games and contests.
It possible but requires a lot of effort to do so.
You go to Spotlight, contests and events and then choose the competition. Carly4325 on Stardoll
Train, battle, catch, compete, contests, Pal Park, theres always something!
You have contests against other piano players and judges vote on who is best. There is not a lot of competing, but the skill level is very high!
you have to practice a long time till you improve
There is no dragonvale for PC
DragonVale does not have redeem codes.
DragonVale is sometimes referred to as DV.
In Pokemon Battle Arena, Pokemon only compete in battles and contests. However, they do not gain EXP or level up.
The best way to prepare for competition in talent contests is repeated rehearsal. No amount of rehearsal is too much; the more the better. If you can rehearse in front of a small audience at some point (just your family or a group of friends or both is an idea) that will help as well.
No you can't sell the Nursery on DragonVale.