How to make a mini cutscene and end game

I’m very new to Unity and am currently studying a course in Game Design and I have little knowledge when it comes to coding and C#, so i need a lil help with how to code something.

I want it so that when the player character has picked up a certain object and goes to a door and clicks on it, it fades to black and a message pops up before ending the game/closing the application.

I’m almost impressively bad with coding, so you might have to dumb it down a lot.

Thanks!