How to change a tourist visa into a work card in the United States? Is it easy?

I'm glad to answer your question. First of all, you can't apply for a work card on an American tourist visa. The so-called work permit refers to the social security number of the United States, not the work permit that allows you to work. But usually when working in the United States, employers must register social security numbers (work permits) in order to declare personal income tax. Personal annual income affects how much family income tax an individual or family needs to declare a year. Is low income, not only can tax refund, but also can apply for subsidies.