Adobe Premiere Pro is a powerful editing software, which can be used to splice video clips together, using tools that can shave down how long you want a clip to be, separate the audio from video, add your own music, and a lot more.
One of the most powerful tools of Premiere Pro is being able to shorten the clip your editing, what that means is that you can set an in point, where the clip starts, and an out point, where it ends, and then you can import just that bit that you have marked into the timeline.
Some free editing software tools are Clips, and Shotcut, as well as iMovie, if you have an overly expensive phone.