Dealing with mold is never fun. It can cause all kinds of health issues, and it comes with a musky smell that will make your basement (or whatever other area where the mold is growing) unpleasant to spend time in. The fight against mold can be won, however, and your best weapons are ventilation and dryness.
Mold grows best in damp, dark, poorly ventilated areas, so you should try your best to minimize this around your home. Mold spores are everywhere, but unless you provide them with a good place to grow, they won’t start to spread in your home.
In some areas of your home, it might be necessary to install some type of ventilation to improve the odds of keeping mold at bay. If there are any leaks in your home, you should get them taken care of as soon as possible as well, since they could provide the water needed for mold to grow.