In the Davis Wiki you can find information about restaurants, shops, apartment complexes, doctors, dentists, etc.
The university has an informative site for foreign students and scholars. In addition to other useful information, the site has a page with information on health care, and a page with information on visa requirements.
The Sacramento International Airport is 20 miles (32 Km) from Davis and is the best choice for travel. San Francisco, Oakland, and San Jose International Airports are 70-90 miles away.
Summers are warm, sometime hot, and dry. Winters are mild but warm clothing and rain gear are a must. Here is a detailed description.