WOW! Tall order. If there was a way a lot companies would be out of business and we wouldn't have to clean as much. You can't keep mold out but you can prevent it. It's in the air. Spores all around us. Here are tips to prevent it from forming/growing.
Keep the air flowing and the humidity low. I use negative ion generators since I suffered a mold poisoning at work a couple decades ago. Do preventative maintenance on areas where its likely to grow like the shower with a vinegar spray. If you have real problems in the shower, use Wet & Forget Inside to prevent growth, and turn on that overhead fan to get the moisture out of the bathroom when showering.
Inspect under sinks regularly to ensure there are no leaks that will promote mold growth. Closets also can become mold sources cause there is little airflow in there, and if you have containers against the walls for storage.... you can have mold growing on the wall/corners.
Find out what is source of mold. Where are there damp areas? Basement underground walls? Start with a dehumidifier and a moisture gauge.
air circulation and dry; straight vinegar kills the spores
There are several ways to get rid of mold, but most importantly, you need to address the root cause to keep it from returning. This article focuses on the bathroom, but is an overall great article that covers methods of how to remove mold, if bleach is safe to use, and how to prevent it from coming back. Hope this helps! Hugs, Holly
As William said prevention is the key for mold. But it is easy said, but not easily done. If you have time read this guide for mold prevention.