Create table in php from sqlite3 database

I am attempting to create a html table using php to retrieve data from an SQLite3 database. The database contains a table of users and bills with information in each row about each. I am trying to display the table but the page will not load and I cannot figure out what is wrong in my code. Any help would be appreciated, thanks!

My database schema:

CREATE TABLE users(id integer primary key, Username varchar(15), FirstName varchar(15), LastName varchar(15), Email varchar(50), HouseName varchar(20), Phone integer, salt varchar(50), Encrypted_password varchar(50));
CREATE TABLE bills(id integer primary key, HouseName varchar(20), Bill varchar(20), Amount real, PaidBy varchar(20), Date TIMESTAMP DEFAULT CURRENT_TIMESTAMP);

html/php table:

<table>
  <thead>
<tr>
  <th width="100"> Bill</th>
  <th width="100">Amount </th>
  <th width="100">Paid By</th>
  <th width="100">Added On</th>
  <th width="100">You owe</th>
</tr>
  </thead>
  <tbody>
<?php
  require ‘session.php’; 
  require ‘database.php’;
  while(($row = $querybills->fetchArray())) {
  $html .= "<tr><td>"$row['Bill']"</td><td>"$row['Amount']"</td><td>"$row['PaidBy']"</td><td>"$row['Date']"</td><td>"$row['Amount'] / $billscount"</td>   </tr>";
  }
  echo $html;
?>
  </tbody>
</table>

session.php:

<?php
session_start();
require 'database.php';
if(isset($_SESSION['id'])) {
  $db = new Database();
  $queryuser = "SELECT * FROM users WHERE(id = '".$_SESSION['id']."')";
  $user = $db->querySingle($queryuser);

  $querybills = $db->query("SELECT * FROM bills WHERE(HouseName == ".$user['HouseName'].")");
  $bill = $db->querySingle($querybills);
  $billscount = $db->query("SELECT COUNT(*) FROM users WHERE(HouseName == ".$user['HouseName'].")");
} else {
  header('Location:login.php');
}
?>

database.php:

<?php
class Database {

private $database;

function __construct() {
    $this->database = $this->getConnection();
}

function __destruct() {
    $this->database->close();
}

function exec($query) {
    $this->database->exec($query);
}

function query($query) {
    $result = $this->database->query($query);
    return $result;
}

function querySingle($query) {
    $result = $this->database->querySingle($query,true);
    return $result;
}

function prepare($query) {
    return $this->database->prepare($query);
}

function escapeString($string) {
    return $this->database->escapeString($string);
}

private function getConnection() {
    $conn = new SQLite3('bills.db');
    return $conn;
}
}
?>