Teach me how to program

I think you need make sure you are loading the DB library.

I would recommend you reading through all the CI documentation first. It's extremely well written, easy to follow, and will probably prevent the next few posts you were going to make.

If you follow the guide, you will be able to connect to the db, execute a sql query and parse the results.

Codeigniter is simply one of the tools you need to learn to be a successful developer. Always add more tools to your coding arsenal!