Public Health is an interdisciplinary field touching on a wide range of subject areas. This intersectionality means when you do research you won't always search in the same databases.
Below are databases organized by three disciplines that frequently intersect with public health. Databases labeled "Best Bet" will be the most useful for you as they contain content specific to public health.
Public Health - Medicine and Epidemiology
Public Health - Policy and Public Affairs
Public Health - Social Sciences