Using these three programs together will give you a good start if you want to make gameplay videos.
-and as they say, "Well begun is half done".
(Only voice attack can cost money and that's 11$ well spent)

OBS is an open source broadcast & recording engine that allows you to both stream directly to services such as twitch & youtube, as well as record videos with added filters.
It can be found here: Open Broadcaster Software.

VoiceAttack many people are already familiar with. but it can do much more than just interpret commands for games.
-you can even use it to give another AI/Program commands via macros!
It can be found here: VoiceAttack VRS, and on steam.

An alternative (to VoiceAttack) that is free if you have english windows can be found here:
How to use macros with windows voice recognition.

Avidemux is a both simple and advanced video-editing tool, made a long time ago with some powerful CLI-capabilities, and an easy-to-use GUI.
It resides here! (scroll down on the page to find win32/64 dl)

Avidemux wiki is here: Avidemux Wiki.
Avidemux tutorials: Avidemux Youtube channel.


With this setup, it should be fairly easy to get up and running.

subtle_shade.