You need to be a registered user with over 1,000 points for a blog. An advice column is much more difficult to get and requires 25,000 points.
A blog is just like having your own website. They usually focus on a specific topic or hobby. You can post whatever you like that is safe and has no personal information. Advice columns are places where other users ask you questions for help. Finally, we also have clubs which don't require any specific number of points. Clubs are general topics of interest that we approve.