This author has not credited anyone else in this file
Donation Points system
Please log in to find out whether this mod is receiving Donation Points
I feel like it's a pretty good template to start from even if you want to change the way he looks as you're leaving the vault. The saved game starts immediately after changing your appearance at the mirror.
Just add the save file to your Fallout 4 saves folder probably at C:\Users\YourUsernameHere\Documents\My Games\Fallout4\Saves