It takes most new writers a while to break into the business, but if you keep at it, eventually you will sell something. Don't give up on a story after 1 or 2 rejections. Submit that story until you run out of markets. The best response to a rejection is another story. If you get a rejection from a market, send them another story.
Many editors reward perseverance.
Don't get discouraged. The difference between the amateur and the professional writer is that the professional didn't quit.