I have requirement where I need to store users ip, device information, user_agent, etc. information for on url on my site. How do I go about this? 
This data will be used later as stats (which device hitting more, which locations etc.) 
I can see that Google analytics helps in tracking for entire site.
How do I enable it to track only for one specific url on my site and track all information mentioned above?
If you add your tracking code only on the one web page you wish to track, then you should be able to accomplish your goal.  Just to clarify, if you have two web pages, trackme.html and donottrackme.html, you would place the Google Analytics tracking code only on trackme.html.  IP, device information, user agent, etc. should be visible within your dashboard.
Track users using Google analytics for one url on website