"It's your turn to ___" means "You should do ___ next because you're the next in order."

You can use this phrase to say who need to do a job next, like sweeping the floor at home or hosting a meeting for your club:

It's Jamie's turn to host.

You can also use "It's ___'s turn" for things that people want to do. For example, a child who wants to play a video game might say this to her parents:

It was my turn to play next, but he stole it from me!