What if you define a function with a name func? what will happen then?

Answer 1

First, we know that the reserved word "def" is who indicates that will define a function. Then we call the function and specify the names of the input parameters.
So if you define a function called "func", it will serve normally like any other name, since what defines the function is def not the name of this.

List of reserved names:
and, as, assert, break, class, continue, def, del, elif,
else, except, finally, for, from, global, if, import, in, is,
lambda, nonlocal, not, or, pass, raise, return,
try, while, with, yield.

Answer 2

Nothing

Answer 3

as said by Antonio ...