Intent to Use Marks. When you file an intent-to-use application, your mark may be examined and approved for publication, but registration is not granted until you file a document with the USPTO establishing that you've begun using the mark. So, in practical terms, you have no trademark rights until you start selling goods and services associated with the mark. Or as they say, 'no trade; no trademark.'
(Note: If you are asking, when does the mark show up within the USPTO trademark registration system (TARR), that happens fairly quickly, usually within