qrest system

i am makeing a 2d sidescrolling offies sim for fbla but i wont to put in a qrest system like you talk to some one then you go to a computer and pres e and it wold then take you to the next level or unlock the next npc qrest to do how wold i do that ples help

ps i have dislexsya

but i wont it wer i pres e on a object like a computer and then it unlock the npc so you can speek to them and get teliported to next level how wold i do that?