How do i create intros before combat levels in the level editor?

im creating my first campaign and i came to the point where i gotta make the intro for the 1st level. everything is set, i've made all the dialogues etc but i cant understand how i can do so that when the player gets in the car, he goes to the combat part or another floor of intro. I've asked ai, watched videos but i really can't understand how to do it. Help would be appreciated