I want to do the entire thing in third person, but the game always says " you" when I enter another room.
You can change most of these messages. You just need to find/"translate" the original ones.
Sadly, I don't know the exact location of everything, I'm new as well lol ^^
A lot of the messages are set to use specifically the word "You". For the "You can see ..." when you enter a room that's the Template called "SeeListHeader". You can see it if you turn on Show Library Elements, and change it to "Bob can see..."
But there are many more generic responses to verbs that use the word "You". Like DefaultJump has "You jump, but nothing happens."
Unless there's a way to turn every instance of "You" into the word you want... you'd have to manually edit all of them.
If you are using the desktop version you can change the templates. http://docs.textadventures.co.uk/quest/translating_quest.html