You won't do anything I say but here it goes. I don't know why I bother with this.
Making an MMO is most likely one of the hardest things in game development, and it's up there in software development in general. It's impossible for one person to even understand the whole system once it's done, research has shown that on big projects, there isn't even one person who understands absolutely everything.
Of course there are exceptions to this rule, surely Torvalds knows everything about Linux and Stroustrup about C++, etc. But those people are outliers.
A high level overview of everything in it is
>game engine
rendering, shading, D3D/OpenGL integration, animation, VFXs, multi platform packaging, networking, security, physics, etc
>game logic
coding the game on top of the engine
>networking
coding the server
>anticheat
because it's an mmo
>3d main assets
models, animations, textures, skeletons, design, etc
>3d secondary assets
props, buildings, terrain, vegetation and see above what they all need
>music
audio, songs, voices
As you can see this is way too much for someone who doesn't even know C/C++
So what do I suggest?
If you're still adamant on doing it, first of all get these books
>Rapid development by Steve McConnell
>Code Clean by Cecil Martin
>Software Engineering by Ian Sommerville
If you are not disciplined enough to read them, give up. Except the third one which shouldn't be read from cover to cover, it's a reference book where you read the chapter you need. These books will teach you how to organize your project.
Now onto the project, there is a design model called Design-To-Tools. Basically, it means you use an existing tool for all of the project and code as little as possible. This means that you use ready-made solutions for about 80% of your project, and this is the only way you could ever hope to finish your project. Yes, even a SaaS as your server. You want to use as many "as a service" things as possible.