There’s no set “apprentice” period in writing and many writers feel they’re learning through their entire career, even with many books under their belts. If you’re just starting out, focus on learning your craft. Read as much and as widely as you can. Practice translating emotion and concrete detail onto the page. Seek out other writers for support and feedback. Take a class to develop your skills. Give yourself the time and opportunity to practice and improve. Thinking about publishing too early in the process can make some beginning writers feel anxious and disappointed. Even worse, it can lead writers to bad decisions, such as falling prey to a publishing scam out of an over-eagerness to be published.
Make choices about submitting for publication based on the quality of your work. When you think it can stand up to what’s published in the journals and books you read you may be ready. For some writers, the journey to this point might be a year. For others, it might be a decade.
Consider your motivation to write. Publishing may certainly be one. But what are the others? What does it satisfy for you that nothing else can? Why is it important to you? Focusing on those qualities as you develop your craft might give you the sense of accomplishment you’re seeking in publication.