The missing information is a full description of your environment
Platform, does Symbolic Link available, kind of administration tool (cPanel, WHM, ...), do you have a dedicated server, do you have MySQL root login, ....

All these element are important to define an architecture.
Each environment is specific and the answer depends on your specific case.
The video can only explain the concept and it can just try illustrate a general case - not a specific one. We try to do specific case with cPanel that seems to be widely used.


Q1) Create an independent "fresh" slave site that will be the "main" website where you will store the users. It is recommended to not use the master website for that. The master should better be used as a repository or libarary of extensions.
Do the same as in the video.

Q2) Start to create the domain in your HTTP administration tools that you have not mentionned.
All depends your HTTP Server configuration.
If you follow the video and that you are using cPanel.

"Main" wensite (not the master)
cPanel Add On domain = dasouth.com
Document root = {home}/domains/dasouth.com/public_html
That will become /home/MASTER/domains/dasouth.com/public_html

Slave 'dasouthtv" in cPanel AddOn
Domain = dasouthtv.com
Document root = {home}/domains/dasouthtv.com/public_html
That will become /home/MASTER/domains/dasouthtv.com/public_html

In this case, the JMS templates become
Domain list = www.{site_id}.com
Deploy directory = /home/MASTER/domains/{site_id}.com/public_html

Same rule can be use to create the "newFresh" slave site.
And another similar one to create the "sharing" rule with site ID = dasouthtv

If you want that we confgure your environment, we also provide billlable support that you can order at
www.jms2win.com/download?page=shop.produ...35&category_id=1

Perhaps you could start to reproduce the tutorial video to understand the concept before trying create domain and have independent DB.
You need good MySQL administration skill to setup the MySQL user correctly to accept sharing accross DB. If you are using shared hosting, in general you can share in the same DB but less frequently accross DB.
Again this depends on your environment.