Q. My piece wasn't accepted. What now?"
A: First off, relax. Even the best, most experienced writers receive rejections constantly. "No" is devastating when you think it is the end of a conversation. It's no big deal when you realize it can be the beginning of a conversation that leads to "yes." So: take rejection as information, and run with it. Consider why your piece wasn’t accepted and focus on improving those areas. If the editor responded to you personally, thank him/her — and see if you can find out what would have made your piece more valuable, and whether there are other ideas they would be interested in hearing from you on in the future.