Fix a simple PHP/MySQL site with SQL Connect errors

I'm looking for a medium-term relationship with a PHP/MySQL guru. At first, it's a moderately simple fix. The site is online cpd dot com dot au. Later, I'd also like to update that site to use newer mysqli functions so that it can be upgraded to newer PHP versions. I'd also like to investigate a reskinning/redesign. I have other sites that also need converting to mysqli, and documentation.