so in this tutorial we will run the 2 folder /var/www/forlder1 and /var/www/forlder2 as 2 different service(sites) on 2 different tcp ports 80 and 8080. first you need to stop apache.
then you need to go to /etc/apache2 folder and open up ports.conf then you will see the fallowing lines:

NameVirtualHost *:80
Listen 80

so will add 2 more to make it look like this

NameVirtualHost *:80
NameVirtualHost *:8080
Listen 80
Listen 8080

Now you can open the folder sites-available and open the file default
you may see something like this or with more or less text:

<VirtualHost *:80>
    DocumentRoot /var/www/

<Directory />
    Options FollowSymLinks
    AllowOverride All
  </Directory>

  <Directory /var/www/>
    Options Indexes FollowSymLinks MultiViews
    AllowOverride All
    Order allow,deny
    allow from all
  </Directory>

  ScriptAlias /cgi-bin/ /usr/lib/cgi-bin/
  <Directory "/usr/lib/cgi-bin">
    AllowOverride All
    Options +ExecCGI -MultiViews +SymLinksIfOwnerMatch
    Order allow,deny
    Allow from all
  </Directory>

  ErrorLog ${APACHE_LOG_DIR}/error.log

  # Possible values include: debug, info, notice, warn, error, crit,
  # alert, emerg.
  LogLevel warn

  CustomLog ${APACHE_LOG_DIR}/access.log combined
</VirtualHost>

first you need to change the folder from /var/www to /var/www/folder1/ and then you need to duplicate the same thing again in the same file but change the port to 8080 and the folder to /var/www/folder2 like so:

<VirtualHost *:80>
    DocumentRoot /var/www/folder1

<Directory />
    Options FollowSymLinks
    AllowOverride All
  </Directory>

  <Directory /var/www/folder1>
    Options Indexes FollowSymLinks MultiViews
    AllowOverride All
    Order allow,deny
    allow from all
  </Directory>

  ScriptAlias /cgi-bin/ /usr/lib/cgi-bin/
  <Directory "/usr/lib/cgi-bin">
    AllowOverride All
    Options +ExecCGI -MultiViews +SymLinksIfOwnerMatch
    Order allow,deny
    Allow from all
  </Directory>

  ErrorLog ${APACHE_LOG_DIR}/error.log

  # Possible values include: debug, info, notice, warn, error, crit,
  # alert, emerg.
  LogLevel warn

  CustomLog ${APACHE_LOG_DIR}/access.log combined
</VirtualHost>

<VirtualHost *:8080>
    DocumentRoot /var/www/folder2

<Directory />
    Options FollowSymLinks
    AllowOverride All
  </Directory>

  <Directory /var/www/folder2>
    Options Indexes FollowSymLinks MultiViews
    AllowOverride All
    Order allow,deny
    allow from all
  </Directory>

  ScriptAlias /cgi-bin/ /usr/lib/cgi-bin/
  <Directory "/usr/lib/cgi-bin">
    AllowOverride All
    Options +ExecCGI -MultiViews +SymLinksIfOwnerMatch
    Order allow,deny
    Allow from all
  </Directory>

  ErrorLog ${APACHE_LOG_DIR}/error.log

  # Possible values include: debug, info, notice, warn, error, crit,
  # alert, emerg.
  LogLevel warn

  CustomLog ${APACHE_LOG_DIR}/access.log combined
</VirtualHost>

and then service apache2 start