I want to host more WP sites on WAMP server at the same time.
How to do that?
YES. You can make sub-folders in www and make different WP websites. But be careful with the database configuration. Installing WP does nothing but coping some PHP files to that specific folder. All the data is saved in database and inside that specific folder itself (E.g. config php files).
I would recommend you to download XAMPP. Basically WordPress is built on PHP and XAMPP has support for PHP. First download it and configure it then go to the installation directory and go to xampp>htdocs> then make a new folder 'project' and then unzip the WordPress files in that folder. After that read the manual provided ant xampp's website and follow it. Basically you can build your WordPress website on Xampp.
EDIT Oh sorry for not understanding the question properly.
Now do this.
step 1: host the different websites in htdocs/ folder in xampp. You can host many websites as you want.
step 2: Then go to xampp/apache/conf/httpd.conf and uncomment the line which says this. For uncomment delete the '#' character.
Include conf/extra/httpd-vhosts.conf
step 3: Go to xampp/apache/conf/extra/httpd-vhosts.conf
Create the setup like this
NameVirtualHost *:80
<VirtualHost *:80>
DocumentRoot "C:/xampp/htdocs/xampp"
ServerName xampp
#ServerAlias
</VirtualHost>
<VirtualHost *:80>
DocumentRoot "C:/xampp/htdocs/site1"
ServerName site1.com
ServerAlias www.site1.com
</VirtualHost>
<VirtualHost *:80>
DocumentRoot "C:/xampp/htdocs/site2"
ServerName site2.com
ServerAlias www.site2.com
</VirtualHost>