It's not as easy as you might think to do what you want in this case, but it is instructive. This is an example where the shape of the data is not right for your needs so you can force it in Tableau but it is better to pre-process the data if possible.
The Superstore data records are per order, with multiple dates, rather than per day, with multiple event counts. You need to reshape your data from the former to the latter using Custom SQL which may sound terrifying but isn't. You Edit the Data Connection and choose Custom SQL instead of Single Table and then do something like the following, which also works with database data:
SELECT [Orders$].[Order Date] AS [Date],
1 AS [Orders],
0 AS [Shipments]
SELECT [Orders$].[Ship Date] AS [Date],
0 AS [Orders],
1 AS [Shipments]
Then it becomes trivial to do what you want. The alternative is to use a Dashboard but the lines will be in separate panes. The self-join data blend I also included is not worth it because it won't allow you to change the granularity at which you view the dates.
All three options are included in the attached packaged workbook (TWBX). Good luck, you started with one of the trick problems.
Somebody give Zach a gold star (or better, a beer)! Thanks man. I knew there must be more to it than just dragging and dropping in the tool...
This is the same problem I have been trying to solve with request received / job completed dates. Thank you!
I am new to SQL and wondering what is the use of the $ at the end of the Orders table name in the Select statements.
The $ is used because Orders is a tab in an Excel spreadsheet rather than a table in a DB.