Need some help with multisite, noob here

I’ve this site: http://myupes.in and I want to add blog page to the site with the URL: http://myupes.in/blogsandarticles. I want to make the page where people can register, post blogs, edit their blogs just as other blogging sites allow. So, how to do that? Will I have to install one more WordPress for this? Please help, I’m a noob for WordPress. Your help in any form would be appreciated. Thank you.