cola_addict I don't have much to say about the story right now, but there aren't obvious flaws and it looks like the sort of thing I enjoy. It's a solid start.
I think you write really well... when you stick to the basics. Your grammar doesn't have many issues, just some slip-ups here and there:
"Noticing there are so much background noises jumbling together with the song, he decides to step closer to the bench."
It should be "[...] there is so much background noise [...]". That's not the problem, though. The problem is this sort of sentence:
"With an old, worn-out guitar in hands so feeble that one might suspect those are of an old man, he tries strumming a few cords but unable to stop his shaking hands."
It's really stiff and awkward. There's also this:
"He forgot to ride upon the waves of momentum crashing around him. Perhaps even more so, he did not pay attention to any of those. Only when those opportunities became prevalent and saturated did he start to take advantage of them."
I can barely understand what you're trying to say here.
I'll give the same advice I've written not too long ago: stick to short sentences and paragraphs with simple vocabulary. When you try writing fancy, complex sentences, you often end up with stiff and confusing text. Try sounding more natural instead. Drop overly formal words and expressions, come up with more straightforward ways of saying something, and in general just write like you talk. Of course, you can keep some level of formal and even flowery language, just make sure you're not going beyond your actual level. If you need some help, try Scribens and follow its suggestions to rephrase things in simpler ways.