need to find a file, dont remember the name

MacPro, early 2009;

8 Gb Ram;

4 internal Hard drives & 4 external hard drives,

MacOSC Yosemite10.10.5;

2.66 GHz Quad Core Intl xeon

Need to find a file, can't remember file name BUT know some key words in the file.

Tried spotlight and easy find, went to app store and searched Utilities for a n app to help, but too many apps, did not know what to look for in an app