QUESTION: Every library has thousands of items! How are you supposed to find anything!?
ANSWER: the Library's Catalog!
Each library compiles a list of everything the library owns and posts it online in a catalog. Before the internet, each item was put on a 3X5 card, so sometimes the catalog is referred to as the card catalog.
Your library will have several computers where you can search for information by subject, keyword, author's name, or book title. Additionally, your library will have a link to its library catalog online from their web page.
When searching the catalog, look for the call number, which is a special number that will help you locate the item for which you are looking. Keep a pen and paper handy to jot down these tricky numbers!
If you are having troubles finding items in the catalog, consult a librarian!