There is now maybe easier way to do screencasts and videos
OBS
Open Broadcaster Software
https://obsproject.com/fi?fbclid=IwAR38aJ3LZNDwquAallyJ7e0mxMUKY7YRiJgxpfSOvXfhyZ0rUnonh35J7nY
Or this:
VokoscreenNG: Open Source Screencasting Tool
For video editing there is also Kdenlive, you can install it like this
Open terminal, write
sudo apt-get update
Press Enter
sudo apt-get install kdenlive
If it wants to install addition software packages say yes to all .
Video recording and making the old school way:
Ask TWIL: How to Make a Screencast on Ubuntu / Linux
By the way, one of the best video editors in linux and my favourite is Kdenlive .