Can I find a free place to stay when I travel to the United States and Canada with my backpack? Can the church stay for free?

1) There are basically no free places to stay. Of course, the church can't stay for free. Free accommodation means you should have friends there. If you want to find a cheap place to live, you can find a youth hostel, but there are requirements for age, and you can't live when you are old.

2) This is not a question of whether you can find a short-term job, but whether you can set up a stall to sell gadgets. This is against the law. Tourist visa holders are not allowed to work, including short-term jobs, and of course they are not allowed to do small businesses. If you go to America and say that in the interview, you will definitely be refused a visa. But there are opportunities. But if you are caught, it means that you can't enter the country again.