Multi-site creation question

I followed this tutorial(Drupal 7) but it not worked for me(Drupal 8):

Multi-site in subdirectories https://www.drupal.org/docs/7/multisite-drupal/multi-site-in-subdirectories

My Drupal is on a Virtual Machine with only access via IP, not hostname.

This is my enviroment:

• CentOs 7 with SELinux(mode: enforcing)
• Varnish 4.0.3
• Apache 2.4.23
• Drupal 8.2.4

I need to create the next structure of sites:

• / <-- First site
• /site2 <-- Second site
• /site3 <-- Third site

In the file sites/sites.php i have:

• $sites['localhost.site2'] = 'site2';

I've recently started learning about how to setup a multi-site drupal web page.

I am working on a web site for a national veterans organization. The question has come us asking if the different states can be part of the site. The national site name would be SOA.COM. The Florida State site would be either FL.SOA.COM or SOA.COM/FL - probably the first.

At this point, I do not have a question about how to set it up, but the practicality of this approach.

Hi, I am new to drupal, have it installed and up and running. I am experimenting with creating a Main Site where users can select an option to create their own site. When the user clicks to create a new site I want to then automatically create a new database for the user, create a new folder on the server for the users site, copy a default site to their folder, replace the template with a specific template the users created, setup all the permissions and accounts, and take the user to their actuall site. The site should already be installed and not go through any drupal setup process.