While each database will be different and offer different tools, they all will function in basically the same way. A database will often offer tutorials on how to use it's unique interface, so upon opening a database for the first time, be sure to seek out and view those tutorials.
You can also:
Visit the Reference Desk in the BPCC Library during hours of normal operation.
Call the Library at 678-6275 or the reference desk at 678-6423.
Email the reference librarian at email@example.com or contact your subject librarian directly.