how to find if the person attend the session how many time?

bbsin 

Create a pivot table based on the data, and add the data to the Data Model:

First, add the Date field to the Rows area.

Right-click any date and select Group...

Select Months, then click OK.

(If your data span multiple calendar years, also tick Years)

This creates a new field Date (Month). Drag this to the Filter area.

Next, add Event to the Rows area and Type to the Columns area (or vice versa if you prefer).

Drag the Email field to the Values area.

Click on Count of Email in the Values area and select Value Field Settings...

Select Distinct Count in the Summarize value field by list. This option is only available if you added the data to the Data Model when you created the pivot table.

Click OK.

The pivot table looks like this in tabular layout:

You can select single or multiple months in the Filter drop-down.

bbsin 

Here is the workbook with the pivot table.