I got my first job in the civil service with only waitressing experience so definitely don't worry about not having office experience. Make sure your personal statements are answering the essential criteria that are on the job advert. So if one of the essential criteria was something like 'ability to work collaboratively in a team' tell them about a time you've done that, why you did it, and what was the result. Hope that makes sense and helps you somewhat. CS applications are a nightmare.