Crown Prince/Princess
Heir to the Kingdom, Crowned King or Sovereign Queen upon death of the previous monarch.
Actual duties may not be given to Crowned Prince or Princess until they reach the age of majority
Spouse before coronation: Princess or Duke
If children born before coronation: the Heir - typically the firstborn -Viceroy Prince or Princess , other children are a Prince or Princess
Requirements
Typically a Prince of Princess is a hereditary title, with the oldest child - the Viceroy - eligible to take up duties once they've reached the age of majority. Until then they are Duke or Duchess.
Often they will spend their late teens and early 20s living in the capital, shadowing local levels of government and learning the laws and customs of their people. It is expected of them to also join the military as an officer and have an understanding of combat and strategies.
Duties
Ruler of a Province/Princedom and in line to rule the Kingdom. Traditionally, this title belongs to the oldest son of a ruling King, but in the West Archway Kingdom some monarchs will instead crown the oldest child, regardless of gender, as long as they've proven themselves capable.
Responsibilities
The Crown Prince or Princess is tasked with the future management of their entire kingdom. They often are put in charge of Princedom that the royal estates are located on to prove their capabilities to both their parents and to the people.
They will also be military trained, and may be called into leading troops in conflicts.
Accoutrements & Equipment
Prince and Princess are entitled to wear a crown if they so desire. a Crown Prince or Princess is expected to for any and all public appearances.