Hello Cecille

Thank you for your purchase.

For the username, you can use our placeholder %CURRENT_USER_LOGIN% as a predefined value for the column, but if you hit "Apply and add new", that predefined value will be lost, so my advice would be to remove that with some custom CSS, like explained on this link.

As for the timestamp:

1. Create a column and name it "Updated" for example

2. In Column Settings, set the data to be DateTime EDITING - None

3. Go to your database, and find this table (you can see the database table name in the Editing tab above the table). There,run this query: 

ALTER TABLE `table_name` CHANGE `updated` `updated` DATETIME NULL DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP;

That's it.