Joining with + and str() works, but it gets messy quickly. Python has a much nicer way: the f-string. Put an f just before the opening quote, then write variables inside curly brackets { }:

name = "Sam"
age = 12
print(f"{name} is {age} years old")

Python replaces each {...} with the value inside it. No str(), no +, no worrying about spaces: the spaces are exactly the ones you typed.

You can put any calculation inside the brackets, not just a variable:

price = 4
quantity = 3
print(f"{quantity} at {price} each costs {price * quantity}")