Your hosting provider has likely already taken care of this for you.
In order to test, create a blank page on your server with this code:
$ch = curl_init('https://www.howsmyssl.com/a/check');
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
$data = curl_exec($ch);
$json = json_decode($data);
That will tell you the TLS version installed. If it returns 1.2 you are all set, otherwise contact your hosting provider to get it updated.