The best site to watch the Victorious show for free is OviGuide.com. The show can be viewed on the following link http://www.ovguide.com/tv/victorious.htm. Other sites that you can visit to watch the Victorious show are Nick.com and Sidereel.com.
If you have Comcast, you can get the Xfinity app and search victorious and watch there, or YouTube search: victorious full episodes. Or go to Nickelodeon.com and search victorious and watch shows there.