Hello Sol! While in season, rehearsals could take up to 6-8 hours a day. It varies depending on the company. Also the ballet “hierarchy” would go as follows: corps de ballet, demi soloist, soloist, principal dancer , prima. Depending on the productions, companies organize auditions or if they see potential in someone they choose him/her. It is not always a fair system so a lot of bribing/blackmail goes on for obtaining higher positions.