How to pivot from Client Services to Marketing?

After a 9-month job hunt I finally landed an entry level position as a client services rep at a blue chip company. My team works in my cities public transit dept’s HQ and handles all of their imaging and mail; I work in the mail room, essentially.

I’ve wanted to work for the city for a while, and this seemed like my in. Now I’m wondering what the best way to approach making the switch from my company to our client’s marketing department. I figure I’ll need to put at least a year into this position first.

I’m 26 and I have a degree in journalism. I minored in professional writing, too.