corrections

<!DOCTYPE html>
<html>

<head>
  <meta charset="utf-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <meta name="description" content="">
  <meta name="keywords" content="">
  <meta name="generator" content="Responsive Site Designer 1.5.1419">
  <title>Share to teach</title>
  <link rel="stylesheet" href="css/coffeegrinder.min.css">
  <link rel="stylesheet" href="css/wireframe-theme.min.css">
  <script>document.createElement( "picture" );</script>
  <script src="js/picturefill.min.js" class="picturefill" async="async"></script>
  <link rel="stylesheet" href="css/main.css">
</head>

<?php
  $name = $_POST["myname"];
  $surname = $_POST["mysurname"];
  $email = $_POST["myemail"];
  $username = $_POST["myusername"];
  $password = $_POST["pass1"];
  $country = $_POST["mycountry"];

  //On the line below, there is a mistake with an open bracket (
  //Remove it
  $city = ($_POST["mycity"];
  $type = $_POST["mytype"];
  $school = $_POST["myschool"];

  print($name);


require_once("dd.php");

//Now that config.php is part of this file. It will suffice to use $db as the connection variable
// or you can still assing $conn = $db and work

//In case you decided to use $connection = mysqli_connect(...)
///Then you can check here with $connection

if (!$conn) {
    die('Connect Error: ' . mysqli_connect_error());
}


//In your insert statement here. You are not suppose to have double quates around variables.
// That is where you have values. they are suppose to be single quotes
//Inserting double quotes fits those values as strings. and not their content
mysqli_query($conn,"INSERT INTO `users`( `user_name`, `password`, `first_name`, `last_name`, `school`, `email`, `country`, `city`)
 VALUES ('"$username"','"$password"','"$name"','"$surname"','"$school"','"$email"','"$country"','"$city"')");

/*
Try any of these two options
$query = mysqli_query("INSERT INTO `users` (`user_name`, `password`, `first_name`, `last_name`, `school`, `email`, `country`, `city`)
    VALUES ('$username', '$password', '$name', '$surname', '$school', '$email', '$country', '$city');

$result = mysqli_query($conn, $query);

//Or you can still use this
mysqli_query($conn, "INSERT INTO `users` (`user_name`, `password`, `first_name`, `last_name`, `school`, `email`, `country`, `city`)
    VALUES ('$username', '$password', '$name', '$surname', '$school', '$email', '$country', '$city');

    */
mysqli_close($conn);

?>

<html>

<form align="left" name="form1" method="onload" action="index.html">

</html>

<script>
 alert("The form was submitted");
</script>

<div id='fg_membersite_content'>
<h2>Follow link to log in</h2>
<ul>
<li><a href='login.php'>Login</a></li>
</ul>
</div>
</html>