First off, I think it's great that you're connecting the question of who our favorite authors are with becoming a writer yourself. After all, one of the best ways to become a better writer (besides writing, of course!) is to read, read, read! I like different authors for different moods, but three of my favorite are Brandon Sanderson for my nerdy moods, Malcom Gladwell when I feel like I want to find a new way of looking at things, and Terry Pratchett when I want to indulge in some silliness.
Thanks for the great question!
Wow, favorite author is tricky question. I think that the genre matters a great deal to your question. For fiction, I love Nora Roberts and James Patterson. I love to read biographies as well so Water Isaacson is good there. I also like Malcolm Gladwell for non-fiction. These are just the ones that come to mind in the moment. I make sure to read at least 100 books a year just to be exposed to as many people as possible.
By the way, I think that you can be a writer no matter what career you choose. It can be done with anything else. If you want to be a writer, I think that the most important thing is to write, even if it is just for yourself. Make sure to journal to just have a daily practice. In addition, make sure that you are sharing your writing in order to get feedback and constantly be improving.