Mold in the house

Hi mummies! I'm originally not from Singapore, and have never been dealing with mold before, only in last 2 years I realized that the place we leave in is quite moldy..(I know its sound stupid but I really didnt know how it looks like and didnt even think of it)...I trying to remove it with different chemicals but it's still coming back, like in bathroom walls and kitchen, I scared to even imagine what happens in aircon (even though we have service cleaning it)..anyway..any tips and tricks you can recommend please? I'm so tired of fighting with it, and mostly very worried about my son, he is allergic to dust & mold..Thanks for advise 🙏