I was able to create an ECT and the first three columns of data that I used to create the ECT display on the portal.
The only issue I am running into is that I want to add more columns to the existing ECT in designer (that I created), but apparently either I have to recreate the ECT unless there is a workaround. One of the articles I found indicated it may not be possible to add columns to an existing ECT because the BCS has certain limitations and this may be one of them, but I don't know that for sure since the article was a bit vague. However, when I went to The Portal and noticed under (Lists-> Employees-> List (in the Ribbon) -> List Settings -> ‘Columns’ heading you can see the other columns that I added to the ECT, but is not displaying on the portal for 'Employees'. So, we know the ECT has been created and other columns added (that don't display for the end user to view), but it’s a matter of whether it needs to be re-created to pull the rest of the columns in the site to be viewable to the end user.
Many thanks in advance for your assistance. :)