whereis doesn't locate files, because
whereis command is not intended to be used for that.
whereis - locate the binary, source, and manual page files for a command
whereis locates source/binary and manuals sections for specified
files. The supplied names are first stripped of leading pathname
components and any (single) trailing extension of the form .ext, for
example, .c. Prefixes of s. resulting from use of source code control
are also dealt with. whereis then attempts to locate the desired
program in a list of standard Linux places.
For more information type
man whereis in your terminal to refer the
man page. For finding a file you have to use commands like