Tracks have two kinds of rights: the author one (the composer) and the phonogram one (the one who executed the track). To use tracks in your video, you should have the licenses from both sides.
You can also create your very own tracks or use a free license one. Websites like Musopen, Archive.org, Freesound.org, Free Music Archive and incompetech.com are filled with options.
Also, you don't need to use a soundtrack in your video. You can explore sounds and silences too.
Don't forget to credit every sound you use.