Touching things while impure

“Hello sir i am asking a question which has made my sons life miserable.

Sir my son said that he was a unware of the rule of purity in islam and he lives in that state for about two three years. He thinks everythings in our house is najis. He said that he used to have urine on my trouser and i made things najis. Also when he had urine on underwear and then wet semen transfered to other objects he thought it was fine. Now he had touched many things while wet where he thinks are najis. He wore clothes during that time which some of it might have not been washed. There are blankets and other staff. Remote control all of them he considers najis becuase he touched them and we have not washed. I wanted to tell him to consider everything paak but i wanted to consult a knowledgable person. What is your view.”