Whats a good way to start a story?

the MC is a 15 yo girl and she is being chased into a different world by 2 20 yo men. she is found in our world by 2 16 yo kids who help her. should i start in the viewpoint of the 2 16 yolds or with the MC running from the 2 20 yo and why? THX!!! ps yes i know im using shorthand i use normal writing in my book.