If you're practicing by writing a blog script, there's no reason not to use a loop either. Always design with the other side of the tunnel in sight - who would want a blog that only ever displayed a single post? Loops can be used to display a single item, or multiple items, the beauty of them is that they don't need to know beforehand, they'll just do their job.

As for a useful answer to your question, I have none. Never used CodeIgniter. The name freaks me out, cause the last thing I need is for my computer to spontaneously combust.