To key out your green screen from your filmed video and replace it with another background, place the video and all this you will need to use a video editing software. There are many video editing software that you can use, some of the most well known are Kdenlive and Magix movie edit pro.
Those programs will not only allow you to apply a green screen effect on your videos but also to create a complete “movie” out of 1 or more videos, you can do all kinds of transitions between different videos, mix videos together, add sound, add captions etc. So when you edit your green screen video in one of those programs it will give you the occasion to create a complete awesome video production 🙂
I will show you how to add a green screen effect to your video both in Kdenlive and in Magix Video pro.