I have been approved to become an Apps Developer. I am very new to this.  When i submitted my application, I didn't put a company name or url.   How do I add it now..

 There is currently no facility for editing a developer application.  This information is used internally only, so even adding it won't have any bearing on your app.  You should edit the App's profile (and possibly your own profile) if you wish to market your company along with the app.

Alternately, you could set up a secondary account and set that up as a developer with your company info.