Rajan,
In one line if I have to tell you about your requirements, then they are two.
1: You have to have a
DOMAIN NAME (e.g:
www.moodle.org) registered to show to public that your moodle site is hosted at this address.
2: You have to have a
WEB HOSTING PROVIDER, that will host your domain (mentioned above) to make your site live for public.
I could have guided you in using your own laptop as a working website, but then you have to have a domain of your own to do that, besides what I have been seeing from your posts, it does seems like you dont have idea of web hosting so routing your own domain to your laptop is step further to using a web hosting to host websites.
Like Mary has suggested, use demo moodle site, but you may wont be able to register on moodle.net, and give demo of student self registration and creating courses, as site will reset in an hours time and you can imagine the frown on audience after all the work done on creating a course for demo to be shown after tea break

.
You can, however, show logging in process and those things that can be presented within an hour before slate gets clean, rest show them on your laptop.
If, even after all this, you still want to go with your web address for moodle and ability to present before audience that this is my moodle site, then I'd suggest spending some cash getting a domain and a web host, rest assured I'll stay up all night setting up moodle site on your server to present before your targeted audience with pride tomorrow.