Creating cross-section

What are you trying to do here? Modify the model? Please provide an example. 

Obtain sectional views for a pond or dump. In my case I want to obtain sectional view of a pond to see how the embankment is growing and the changes in the side slope(s).

Use QGIS for work like that using the DEM created by Maps Made Easy. 

How do I get the QCIS program? Is it something I have to purchase? I have not used QCIS before, please can you give a stepwise approach to achieve my goal (cross-sections)? Thank you.

That is beyond the scope of the support we offer. We created the data products. Interpreting them is up to you. 

A quick Google search shows this:

https://www.youtube.com/watch?v=UD0Oumv5y1w