creating functions

The last line hello_student(name) calls the function passing in a variable named name for the name parameter. Since there is no name variable defined you receive the error. Something like this would work:

name = "emily"

def hello_student(name):
    return 'Hello ' + name
hello_student(name)

but that is not what you are being asked to do. Note the variable name and the parameter name are not the same thing.

For task 1 you are to create the hello_student function with a name parameter and return 'Hello ' followed by the value of the name parameter. I have done that above.

For task 2 you are to call the hello_student() function and save the return value to a variable called hello. You had that in your code (although in the wrong place).

If you put the two together you have:

def hello_student(name):
    return 'Hello ' + name

hello=hello_student("emily")

It looks like you overwrote your function with task 2.

Outside of the function this is ok for task 2.

hello=hello_student("emily")

But you will need to restore your code from task 1.