To ask a question and get the response from the user you can do this:

var = input("Question")

var is the variable you want to save the text from the user to.
To print a variable with a string you can do this:

print("Hello", var)

Combining these two things gives this:

name = input("What is your name? ")
print("Hello, ", name)

I need to ask them for their name AND last name but I'm not sure how to do it.

name = input("What is your name?")
print("Hello",name)