On the issue of changing American tourist visa to work visa! thank you

1. You can leave for America from any airport.

2. Your visa type is b 1/b2. As long as your visa is valid, you can enter the customs without re-signing. But when you get to the US Customs, the immigration officer will ask you the purpose of coming to the United States, and then you can tell him that you are here to travel, because the reason for your entry is the same as your visa. As for the reason why you got the visa and entered the customs, it doesn't matter. He won't find out. Mine is b 1/b2. It is legal for me to enter the country in any capacity. Don't worry. As long as you don't bring contraband, meat and seeds when you enter the customs, there is no reason why he won't let you enter the country.