I can't get any jobs as a student on upwork.
I have a good content and article writing skills
I have filled at least 15 proposals but not get accepted. May be my profile is not attractive or It doesn't have any experiences. But I can do this better . Plz someone help me I am a beginner.
Saying that you can do content writing is not the same as demonstrating you can. Clients look for certainty, they won't give you a job just because you say you can do it, they will give it to you only if they see proof of it and they like your work.
Study everything on Upwork's Academy before applying to more jobs https://community.upwork.com/t5/Academy/ct-p/Academy
It takes years of experience to become an expert at something. Malcom Gladwell wrote a a famous book that postulates it takes 10,000 hours of intense practice to become a master at something. And you want to strike out in the business world because "I have a good content and article writing skills," which is not very polished English at all. You wrote, "I have filled at least 15 proposals but not get accepted," also stilted and sub-par writing.
Try your local newspaper or regional magazines and look for work there. Come back in about 10 years or, roughly, after you've got 10,000 hours of intense practice behind you.