First of all, you can search for files directly in Spotlight and in the Finder based search function. In order to run Spotlight search Mac users need to hit simultaneously Command+Spacebar. To open Finder search Mac users need to hit Command+F.
If you want to make file search on a Mac efficient you need to use proper search operators to narrow down your request. File search operators can be divided into two categories: specific, such as file format or general, such as file type.