First YT vid

So, I want to post the first video on my YT channel. A video of me conquering Cledwyn-E's 4k Earth Map in Territorial.io. But I have less idea how to do this than a rock named Joe.

• How do I do this?

• Should I put music over it?

• If so, what song?

• Should I edit the video to be shorter? It's about half an hour long currently.

• What do I do to avoid being copyright struck?

• What editing apps can I use? I want to add text.

• Is it possible to do this for free?

• And what else should I do?