When you start learning back-end development with Python, there are some important basics you need to understand:

1. Data Types and Variables: You should know about different types of data. This includes integers (like whole numbers), floats (like numbers with decimals), strings (like text), and booleans (which can be true or false). For example, 'Hello, World!' is a string, and 42 is an integer.

2. Control Flow: You need to learn how to make your code make decisions using if, elif, and else statements. For example:

   if age >= 18:
       print("Adult")
   

   This code checks if a person's age is 18 or older and prints "Adult" if it is.

3. Functions: Learn how to create and use functions. Functions help you organize your code better. Here’s an example:

   def add(x, y):
       return x + y
   

   This function adds two numbers together.

4. Data Structures: Get to know lists, tuples, sets, and dictionaries. For example, a dictionary helps you store information as pairs, like this: {'name': 'Alice'} where "name" is the key, and "Alice" is the value.

5. Error Handling: You can use try and except to deal with errors in your code smoothly. For example:

   try:
       print(1 / 0)
   except ZeroDivisionError:
       print("Can't divide by zero!")
   

   Here, if you try to divide by zero, it will print a friendly message instead of crashing.

These basics are really important for doing back-end development with Python!