Creation method for Earthbound 2D Battle backgrounds

Hello! First post here, so I apologize in advance for any bad etiquette. I've been lurking on the forums for a while and taking tutorials, but now I wanted to open up what remains as a mystery as a discussion. And that is:

Battle backgrounds! (in Earthbound's style)

For all intents and purposes, let's say I want to remake Earthbound from the ground up, without recurring content. In other words, the game I want to design code for is a turn based RPG in the same style as Final Fantasy I, but with more interesting visuals. That's why having an interesting battle background appeals to me so much.

So, what I'm trying to figure out is how to code this into the actual backgrounds of the game. I found this thread here explaining some of the code in C++, but what I'm looking for is a C# code, or a corresponding option in Unity to create it. (Also, you don't need to provide the code itself, but if you have any advice on how to find it, I would appreciate it!)

My experience in programming comes only from tutorials, so when a new question like this comes, I don't have the answers. Thanks in advance for your patience with a newbie.