Hi,Just because you are in marketing that doesn't make you Radio material, you'll probably need training as the are thing you need to learn such as: Voice projection, Mannerism, Mike Technique, and Interview Skill,and News Compillation and Reading these are all the skill you need to have develop.
You don't just get into Radio because you have a certain experience, people must take Radio serious, and as professional career.
Think about investing in yourself as you did with marketing, surely you didn't just apply for the position taking a risk with no experience or a diploma in this respect you must have gone to some college to earn your right to apply for this job at hand. so you would for radio, it's not all about playing music and saying what you want when you feel like, and dis-obeying the rules of radio discipline is very Important.
I'm not trying to do you down but you must play by the rules.