i have created a website at wordpress http://friendzunited.wordpress.com and i want to add plugins in my site but i can't see the plugin tab in the left side menu bar please me how to add plugins in sites
Wordpress.com can not use plugins. You need to use wordpress.org to install your preferred plugins. Buy a domain name, buy a hosting account, install wordpress.org then add your preferred plugins.
I suggest you to by a domain and a hosting, or you can use free hosting. Then you can use plugins, themes as you want. Good luck
there is no free lunch... you should be satisfied with whatever options they have at wordpress.com. Lot better than blogspot. for plugins you need to host your own site and install wordpress from wordpress.org