What to prepare before our call

Ten minutes of preparation saves twenty minutes of call. Bring what you have; "I don't know" is a fine answer.

What problem are you trying to solve, in one or two sentences?
Which tools do you use today (Power BI, Fabric, Tableau, Excel, Databricks, Snowflake, Azure)?
Where does the data live, and roughly how big is it?
Who uses the reports, and how many people?
What would "done" look like?
Timeline and budget range, if you have one
Who else should join the call?

No file needed for the first call. If you have a report that is acting up, a screenshot is plenty.