Choose several cities that you find appealing. You can probably find somewhere where jobs in your field are plentiful, and that you'd like to live in as well.  Look for cities that have affordable housing and living costs, a wide selection of jobs, available housing, good healthcare facilities, and schools and places of worship adequate to your needs. You also should consider if you have friends of friends or others from your country of origin in that area. Climate in the United States is quite varied; research the seasonal averages to ensure you are comfortable with the local extremes or natural hazards, such as earthquakes or hurricanes. Look at the typical salary for your profession. Examine the Bureau of Labor statistics regarding wages by section of the country and job category to get an idea of the salary you may be able to negotiate in various regions of the country. You can also look on job search websites such as craigslist.com, linkedin.com, indeed.com or others. The Occupational Outlook Handbook provides in depth information about job prospects in most major fields. The information is updated annually and includes information about education or experience needed for the type of job as well as an outlook and a general description of job duties. Some cities are better than others, depending on what you do.  The coasts, San Francisco, New York, Los Angeles are very expensive. You may find those places attractive if you have a very highly paid profession, such as Engineering, Programming, Mathematics and so on. If you have a profession that "can go anywhere" such as nurse, school teacher, doctor, you may want to look for a smaller town that is cheaper to live in and may have not enough professionals. If you are an entrepreneur, you may find smaller towns cheaper, yet less welcoming to foreigners.

TL;DR in Chinese:
了解美国的城市。 搬去美国之前，在选择的城市找找你工作领域的职位。 在工作机会和生活方式之间取得平衡。