Http error 500

My login form php:

<?php session_start(); $_SESSION['message'] = ''; $mysqli = new mysqli('sql201.ezyro.com', 'ezyro_20786443', 'logan1027', 'accounts'); if($_SERVER['REQUEST_METHOD'] == 'POST') { //two passwords are equal if($_POST['PASSWORD'] == $_POST['confirmpassword']){ print_r($_FILES); die; $username = $mysqli->real_escape_string($_POST['username']); $email = $mysqli->real_escape_string($_POST['email']); $password = md5($_POST['password']); //md5 hash password security $avatar_path = $mysqli->real_escape_string('images/' .$_FILES['avatar']['name']); //MAKE SURE FILE TYPE IS IMG if (preg_match("!image", $_FILES['avatar']['type'])){ //copy image to images/ folder if (copy($_FILES['avatar']['tmp_name'], $avatar_path)){ $_SESSION['username'] = $username; $_SESSION['avatar'] = $avatar_path; $sql = "INSERT INTO users (username, email, password, avatar)" . "VALUES ('$username', '$email', '$password', '$avatar_path')"; //if the query is successful, redirect to welcome.php page, done if ($mysqli->query($sql) === true) { $_SESSION['message'] = 'Resgistration was successful we added $username to our list!'; header("location: welcome.php") } } else{ $_SESSION['message'] = "Sorry something went wrong we couldn't add you."; } else{ $_SESSION['message'] = 'Your avatar upload failed'; } else{ $_SESSION['message'] = 'Please only upload GIF, JPG, or PNG IMAGES'; } else{ $_SESSION['message'] = 'Your passwords did not match'; } } } } ?>

<link href="//db.onlinewebfonts.com/c/a4e256ed67403c6ad5d43937ed48a77b?family=Core+Sans+N+W01+35+Light" rel="stylesheet" type="text/css"/> <link rel="stylesheet" href="form.css" type="text/css"> <div class="body-content"> <div class="module"> <h1>Create an account</h1> <form class="form" action="form.php" method="post" enctype="multipart/form-data" autocomplete="off"> <div class="alert alert-error"><?= $_SESSION['message'] ?></div> <input type="text" placeholder="User Name" name="username" required /> <input type="email" placeholder="Email" name="email" required /> <input type="password" placeholder="Password" name="password" autocomplete="new-password" required /> <input type="password" placeholder="Confirm Password" name="confirmpassword" autocomplete="new-password" required /> <div class="avatar"><label>Select your avatar: </label><input type="file" name="avatar" accept="image/*" required /></div> <input type="submit" value="Register" name="register" class="btn btn-block btn-primary" /> </form> </div> </div>

what am I supposed to do I honestly don't know how you are to format the sql login:
$mysqli = new mysqli('sql201.ezyro.com', 'ezyro_20786443', 'logan1027', 'accounts');

ok thank you for helping I will just go to wordpress then untill I learn php properly

got it thank you