Short answers, pulled from the story.
Scholars have fixed the composition date of As You Like It to a period between the end of 1598 and the middle of 1599. External clues include the entry into the Register of the Stationers' Company on the 4th of August 1600 as a work to be stayed until copyright issues were resolved.
Rosalind flees persecution in her uncle Duke Frederick's court accompanied by her cousin Celia seeking safety and love in the Forest of Arden. Orlando a young gentleman falls in love with Rosalind at first sight but is forced to flee home after being persecuted by his older brother Oliver.
Through four acts Rosalind disguises herself as a boy whereupon rustic Phebe becomes infatuated with this Ganymede name carrying homoerotic overtones. The epilogue states explicitly that she or at least the actor playing her is not a woman so a boy actor would be playing a girl disguised as a boy impersonating a girl.
Shrove Tuesday the 20th of February 1599 at Richmond Palace occurred before Elizabeth I by Lord Chamberlain's Men. Another possibility is the 12th of December 1603 at Wilton House Wiltshire home of Mary Sidney before King James by same company renamed King's Men.
As You Like It known as musical comedy contains more songs than any other Shakespeare play. Thomas Morley composed music for It was a lover and his lass living same parish composing music for Shakespeare plays.