How does one install x264 Codec for Kdenlive? I've seen many different tutorials for other software but can't find one for this. Can someone help me out?

I would follow this one (libx codec pack) as this is the original one from the linux repositories.
http://www.videolan.org/developers/x264.html

Or even better, install ffmpeg. If i'm right that contains H.264 and H.265.

But is it not already on you computer? Often that is, and then you only have to edit the settings to make it find it.

H264 is the default rendering codec of Kdenlive.. and probably the most used. (but is also a very old format)

https://invent.kde.org/multimedia/kdenl ... ssues/1256