I want to have a list sheet 2. But in sheet 1, when I type in the
number I want the name in the cell in sheet 2 to automatically come
in.

One way is put this formula in B1 of sheet 1:
=IF(AND(ISNUMBER(A1),A10),INDIRECT("Sheet2!A"&A1) ,"---")

Then type the number in A1 of sheet 1.

This is assuming that the list is in column A of sheet 2.