Peace farside,
Generally speaking, the people of paradise will not sleep for there will be no fatigue in paradise.
"There no sense of fatigue shall touch them..." ( 15:48 )
However, if there is an inhabitant of paradise who desires to sleep, then ofcourse he/she will be able to go to sleep. As Allah says in the Quran:
"Gardens of Eternity which they will enter: beneath them flow (pleasant) rivers: they will have therein all that they wish: thus doth Allah reward the righteous" (16:31)
Peace and Blessings be to the Believers