You could convert the wordpress install in to a WordPress MU site.

http://codex.wordpress.org/Create_A_Network

WIll It affect my old blog???

Hi there,

You could follow the steps from this video on how to host multiple WordPress websites on the same server with Apache Virtual Hosts:

Essentially, what needs to happen is:

• Download a new copy of WordPress with the wget command:

wget wordpress.org/latest.zip

• After that extract the files

unzip latest.zip

• Then move the files to the /var/www/ folder:

mv wordpress /var/www/your_site.com

• Then set the owner of the file to the Apache2 user:

chown -R www-data:www-data /var/www/your_site.com

• After that copy the existing Apache config:

sudo cp /etc/apache2/sites-available/000-default.conf /etc/apache2/sites-available/your_site.conf

• Then enable the new site:

sudo a2ensite

• Run a configtest:

sudo apachectl -t

• If you get Syntax OK reload Apache:

sudo systemctl reload apache2

• Then create a new MySQL database and username. To create the database first access MySQL:

mysql

Then run the following queries:

CREATE DATABASE wp_site;

CREATE USER 'wp_site'@'%' IDENTIFIED BY 'use_secure_password_here';

GRANT ALL PRIVILEGES ON wp_site.* TO 'wp_site'@'%' WITH GREANT OPTION;

• Finally, access the site via your web browser to finish the installation.

Hope that this helps.
Regards,
Bobby