Can not find the Homebrew in the terminal

But in the Mac OS, I use brew to install the setuptools:

aircraftdeMacBook-Pro:~ ldl$ brew install -y setuptools
Updating Homebrew...
==> Auto-updated Homebrew!
Updated 1 tap (homebrew/core).
==> New Formulae
adr-tools                                goad
allure                                   grakn
angular-cli                              iamy                                   zyre
get_iplayer
==> Updated Formulae
aalib                      gspell                     opencore-amr
......
gsl                        opencoarrays
==> Renamed Formulae
grunt -> grunt-cli
==> Deleted Formulae
autotrace  blucat     dvtm       libgc      libtess2   snescom    xplanetfx

Error: No available formula with the name "setuptools" 
==> Searching for a previously deleted formula...
Warning: homebrew/core is shallow clone. To get complete history run:
  git -C "$(brew --repo homebrew/core)" fetch --unshallow

Error: No previously deleted formula found.
==> Searching for similarly named formulae...
Error: No similarly named formulae found.
==> Searching taps...
Error: No formulae found in taps.

I want to find the Homebrew, so I use:

whereis homebrew
whereis Homebrew
whereis brew

All find nothing. how to know the homebrew location, why use the whereis can not find it?