The API is pretty well documented here https://github.com/justintv/Twitch-API
As far as retrieving data from it, I personally prefer PHP (because that’s the only thing I know
), here is a simple example for the things you asked about:
<?php
$json = file_get_contents("https://api.twitch.tv/kraken/channels/lirik");
$api = json_decode($json, true);
echo "Stream title: ".$api['status']."<br>\n";
echo "Game: ".$api['game']."<br>\n";
echo "Followers: ".$api['followers']."<br>\n";
?>