What potential pitfalls should beginners be aware of when starting to learn PHP?

Beginners should be aware of the following potential pitfalls when starting to learn PHP: 1. Not properly sanitizing user input can leave your application vulnerable to security attacks like SQL injection and cross-site scripting. 2. Failing to understand the scope of variables can lead to unexpected behavior in your code. 3. Relying too heavily on copy-pasting code without understanding how it works can hinder your learning progress. To properly sanitize user input, you can use functions like `mysqli_real_escape_string` or prepared statements to prevent SQL injection attacks:

$user_input = $_POST['user_input'];
$clean_input = mysqli_real_escape_string($connection, $user_input);
```

To avoid issues with variable scope, make sure to declare variables in the appropriate scope:

```php
function myFunction() {
    $variable = "Hello";
    echo $variable;
}
```

To improve your understanding of code, take the time to read and understand each line of code you use:

```php
// This code snippet calculates the sum of two numbers
$num1 = 5;
$num2 = 10;
$sum = $num1 + $num2;
echo "The sum is: " . $sum;