If you are looking for video practice files or to add as portfolio items without infringing on any copyrights, youtube is an awesome resource for such videos. It is easy to filter search results on youtube on terms of Creative Commons videos meaning that this videos are free to use in any way shape or form that you feel like.
There are tons of videos on Youtube ranging from news pieces, documentaries, videos of different accents and not limited to interviews that are re-usable over and over again. Feel free to watch the video below to see how to select the correct files.
I appreciate comments and suggestions for future videos. Thanks.