Is Everyone Approved For Adsense?

No not everyone is approved for adsense. There are a number of adsense-related newsgroups with posts from people who post lamenting about how they weren't approved for adsense.

When you sign up for adsense you have to submit the url of your site so that adsense can review and approve it.

You don't have to have a "high" traffic site but your site (or blog) has to have some content on it.