Is there any way to install MS Word or Latex on a Raspberry Pi Zero W?
There is no way to run Microsoft Word direct on a Raspberry Pi because it is compiled for Intel microprocessors. Raspberry Pi uses ARM processors.
To use Latex on a RasPi should not be a problem because it is available from the default Raspbian repository. Just look with
rpi ~$ apt list latex*
and install the packages what you need.
LibreOffice Writer is an open source equivalent to MS Word, and that runs on the Pi. It may be installed by default, but if it's not in the main menu, install it with:
sudo apt update sudo apt install libreoffice-writer
or to install the whole LibreOffice suite:
sudo apt install libreoffice