The first program to try can be -+OpenShot+- (multiplatform).
But if you need more power/features, you can use -+KDEnLive+- (GNU/Linux only, and maybe MacOSX but not Windows).
And if you want to use a newer version than the one that comes with your distribution (either *ubuntu 16.04, 18.04, etc., or even with the Kubuntu-ppa/Backports repo), you can install KDEnLive by means of the -+Flatpack+- system, which works nicely in my first tests {sign user="Xavi" datetime="2018-12-27T12:32:17+00:00"}
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sudo add-apt-repository ppa:alexlarsson/flatpak
sudo apt update
sudo apt install flatpak # install flatpack software
sudo apt install gnome-software-plugin-flatpak # Install the Software Flatpak plugin (optional)
flatpak remote-add --if-not-exists flathub https://flathub.org/repo/flathub.flatpakrepo # -- Add the Flathub repository
flatpak install flathub org.kde.kdenlive # Install KdenLive through Flatpack - KDENLive version 18.12.0 by the time of this writing December 2018 ! on top of Kubuntu 16.04
flatpak run org.kde.kdenlive # Run KdenLive through Flatpack
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