If you want to start developing VSRO (Silkroad Online) and create custom UIs, GUIs, and filters, it would be beneficial to learn C++ because it is the main language used in developing old games like Silkroad Online. Since VSRO is an old project, it relies on relatively old programming technologies, so dealing with the game code and its components requires you to have a good understanding of these technologies.
Why learn C++?
Full control: C++ gives you full control over memory management and performance, which is important in developing games, especially old games like VSRO.
Old software: Since Silkroad Online was developed using old technologies, C++ is the best choice for working on game engines and user interfaces.
Libraries and plugins: You will be able to use old libraries and plugins used with the game or develop custom libraries to enhance certain functions.
Steps after learning C++:
Understanding the game structure: You need to understand the structure of the game server and how to deal with packets and the server API.
Memory Handling: Since older games rely on tight memory management, you may need to learn how to legally hack memory or reverse engineer the internal behavior of the game.
UI/GUI Creation: Learn how to design a modern user interface and link it to the original game code.
Learn the basics of network programming: Since the server relies on network connections between players and the server, you should have a good understanding of network programming and how to handle packets for communication between the client and the server.
Do you need to learn anything else?
Besides C++, you may need to learn:
HTML/CSS/JavaScript: If you plan to create a user interface based on web technologies.
SQL: If you want to work on the game databases.
Graphics Programming: Learn the basics of graphics such as DirectX or OpenGL to improve the graphics in the game.
Time to become good:
Learn C++: Depends on your current level of programming, but it can take 3 to 6 months to become good at C++.
Understanding the VSRO architecture: This can take longer because you need to understand a lot of legacy code, and it can take anywhere from 6 months to a year.
Working on the user interfaces: If you already have experience in designing user interfaces, the work can be faster, but if you are new, it may take you an additional 3-4 months to learn these skills.
Overall, it can take 1-2 years to become proficient in developing and modifying VSRO.