Meal cost challenge

[Emekadavid]

I want to solve a meal cost challenge as part of learning python but when I put the following code which the website gave me, I had two problems:

import math
import os
import random
import re
import sys

# Complete the solve function below.
def solve(meal_cost, tip_percent, tax_percent):

if __name__ == '__main__':
    meal_cost = float(input())

    tip_percent = int(input())

    tax_percent = int(input())

    solve(meal_cost, tip_percent, tax_percent)

The first problem is: 1. My editor gave an Indentation error on the if block. It says it expected an indented block. What does that mean and how do I resolve it?
Second problem: What does the if block mean. i.e

if __name__ == '__main__':...

. What does it actually mean? In my readings I have not come across such an expression. Just a noob still therefore why I am taking the challenge to improve.
Thanks for your help.