view and Content:user issue
If you are using the Unformatted list format used by default from the front page view, you would see the author of the node. This happens if you selected Display author and date information on the settings page for the content type (admin/structure/types/manage/[content type]).



Supposing that you change the format to, for example, Table (which allows you to add fields), when you add the new fields you will notice that Content: Author uid field has the following description:


  The user authoring the content. If you need more fields than the uid add the content: author relationship.


So, you just add a relationship.





Once you do that, you will find the author name between the fields you can add.



As for the Grid format, it doesn't uses fields; that is why you cannot select them.