You can learn a great deal from your superiors and colleagues in daily operation.
Please utilize the useful information you learned.
You should improve not only knowledge but also a telephone skill.
A skill to explain in clear and concise manner needs a long time to gain.
Sometimes you need to “steal” such a skill from your superiors, colleagues, and subordinates.
To do this, listening to others with good skills, or monitoring, is useful.
Try to understand frequently-asked queries. If you find no document for some queries, you should make the document by yourself and keep it at your hand.
Try to understand your unsatisfactory fields and take necessary action by learning with focus and checking FAQ