Upload gambar php native

permisi akang teteh mau tanya.. mau upload gambar di php native. bagaimana ya caranya? saya biasa pake ci jadi agak bingung

ini kodingan script phpnya:

<?php
require_once 'Core/init.php';
 	$_SESSION['page']="Index";

	$error_nb='';
	$success_nb='';
if ($user->Logging()) {
	# code...
	if (Session::get('user_status')=='Admin') {
		Redirect::to('Dashboard');
	}else{
		if (Input::get('submit_neonbox')) {
			if (Token::check( Input::get('token_neonbox') )) {
				if ($transaction->insert(array(
					'id'				=>'',
					'user_code'	=>Session::get('id_user'),
					'category'=>Input::get('order_type_neonbox'),
					'name'		=>Input::get('name_neonbox'),
					'title'		=>Input::get('title_neonbox'),
					'email'		=>Input::get('email_neonbox'),
					'phone'		=>Input::get('phone_neonbox'),
					'explaining_user'=>Input::get('messages_neonbox'),
					'gambar'=>Input::get('gambar'),
					'status'	=>'Negotiation',
					'price'			=>0,
					'price_deal'		=>0,
					'read_admin'		=>0,
					'read_user'			=>1,
					'date'				=>date('Y-m-d')
				))) {

					$success_nb='Your request will be process. We will send email or call you. Thank you!';
				}else{
					$error_nb='Sorry! something problem, please try again';
				}
			}
		}else{
			$error_nb='';
			$success_nb='';
		}