Many editors or publishers like dealing with writers who have an existing track record. It can show that other publications have been interested in your writing and that you have an existing audience for your work.
Building an author profile can take time and effort. Some good ways to start can include entering competitions (and hopefully winning or being shortlisted for some), sending your work to literary (and other) magazines, and making connections across the literary community.
It’s also more and more important to have an online presence - whether that's through social media, a blog or your own website. Pick a format that works for you and keep it on-topic and up-to-date.