How do I determine the name of the cookie that I will set in cURL PHP?

Question

I have this code to scrape bestbuy's website:

<?php
$useragent = 'Mozilla/5.0 (Windows NT 6.2; WOW64; rv:17.0) Gecko/20100101 Firefox/17.0';
$curl_handle=curl_init('https://www.bestbuy.com/');
curl_setopt($curl_handle, CURLOPT_URL,'https://www.bestbuy.com/');
curl_setopt($curl_handle, CURLOPT_CONNECTTIMEOUT, 2);
curl_setopt($curl_handle, CURLOPT_RETURNTRANSFER, 1);
curl_setopt($curl_handle, CURLOPT_COOKIE, '');
curl_setopt($curl_handle, CURLOPT_COOKIEJAR, '');
curl_setopt($curl_handle, CURLOPT_USERAGENT, $useragent);
$query = curl_exec($curl_handle);
curl_close($curl_handle);
?>

But I do not know what am I supposed to put between the quotation marks for the cookies in these lines:

curl_setopt($curl_handle, CURLOPT_COOKIE, '');
curl_setopt($curl_handle, CURLOPT_COOKIEJAR, '');

I am a beginner in scraping so I might have more than one mistake in this code so please help me. Thanks.