There’s no need to be rude. They were asking a simple question, they didn’t mean it in a bad way. And when they asked who the YouTuber was, they had a point. Why would you tell us there’s a YouTuber, then not tell us who made the video?
I really don't know if this was a fever dream or not but I think I saw somewhere that you can now add second floors to your house in sims mobile. If this is true will someone please tell me because I can't see the option in build mode and I don't know if I'm going mad!
Go to the quest and click on the little question mark in the top right corner. It will tell you what you need to do. Usually you have to click on a specific piece of furniture in your home such as a table for example, for the option to appear.