Two of the most valuable lessons I learned in college were to 1. Write everyday. It doesn't have to be serious. It can be a poem, a short story, a research endeavor, a letter, whatever, as long as you get words on a page. Try and shoot for at least 25-30 minutes each day.
2. The first time through a story, essay, book, etc. don't go back and revise. Just keep writing until you have a bare bones draft. This will be far from perfect, and you might even cringe several times going back and reading through it, but it allows a writer to flesh out the main points of the plot, the details of the setting, the basics and quirks of their characters. As you get more comfortable in the story, it will come easier. You will get better at defeating those pesky instances of writer's block, and learn about yourself as a writer, as well. Overtime, it will be easier to figure out ways to get around feelings of writer's block in the future. Everyone gets it. It doesn't matter if you're a beginner or an expert, sometimes our brains just don't cooperate how we'd like them too!
Not at first! When I was in elementary school I was convinced that I was going to play for the New York Yankees! Then, when I got older and into high school, I was really into music and theater. Writing just kind of found me. I'd always been a big reader, and when it came time to start looking into colleges and future career choices, it just seemed to be where I belonged. I'm glad I listened to my instincts!