John 14:3 And if I [Jesus] go and prepare a place for you, I will come back and take you to be with me that you also may be where I am.
The size of the New Jerusalem is found in Revelation 21:15
The angel who talked with me had a measuring rod of gold to measure the city, its gates and its walls. 16The city was laid out like a square, as long as it was wide. He measured the city with the rod and found it to be 12,000 stadia c in length, and as wide and high as it is long. 17The angel measured the wall using human measurement, and it was 144 cubits d thick.
The Population Reference Bureau estimates that about 107 billion people have ever lived. https://www.bbc.com/news/magazine-16870579#:~:text=So%20what%20are%20the%20figures,people%20for%20every%20person%20living.