You are inexperienced - and there's no shortcut you can take to having more experience, it takes time and only time will help.
I don't like what I'm doing right now as the programming language that I'm using is very old
The fact that you are working and gaining professional experience is going to be more important than any particular language at this point in your career. Instead of focusing on the code, focus on the process. Learn and implement best practices in your current workplace.
Does your workplace use unit tests? If not, convince your boss(es) that putting them in will improve the maintainability of the code (and ultimately save money, and then take it upon yourself to implement them and write as many as you can. If you already use them, make sure that you have as close to 100% code coverage as possible.
Does your workplace do code reviews? If not, try to convince your peers and bosses that they're useful, and even if you can't get it fully implemented try to make sure that any code you write is reviewed by someone, even if informally.
Does your workplace have good source control practices? Code conventions? When I was starting my programming career, one thing I went through all our codebase after workhours for a week and eliminated all the "warnings" that visual studio was finding (none of them were bugs, just code that could be made more readable, more explicit, etc.). I spent another week or two adding XML documentation to every function. None of that required that the code be modern, but it helped me be a better software engineer by forcing me to think about cleaner code and better documentation for anything I wrote in the future.
Most of what you do as a developer isn't going to be coding, but engineering - use this job as a starting point to learn the non-code skills and you'll be in a much better position to learn newer, more modern languages in the future.