There are several ways to watch YouTube at school despite restrictions. One way is to use a proxy website or your phone's hot spot network. Another way is to use a VPN, Tor, or proxy services. You can also try using a free extension on Google Chrome to change your IP address. Additionally, you can download YouTube videos to your device and show them to your friends the next day.
If you want to watch YouTube videos at school, you can download them first, and then watch them at school. So you must need a professional YouTube video downloader to download your favorite videos.