I've installed CLion and I plan to start coding on C++. I've also installed Cygwin. I've researched for the last hour or so on how a compiler works and how to use it, but when I selected the compiler on Clion I get the errors
CMake Error: CMake was unable to find a build program corresponding to "Unix Makefiles". CMAKE_MAKE_PROGRAM is not set. You probably need to select a different build tool."
CMake Error: CMAKE_C_COMPILER not set, after EnableLanguage"
and
CMake Error: CMAKE_CXX_COMPILER not set, after EnableLanguage
At first glance it seems to me you are missing a compiler. Do you have a compiler installed (ex: g++) or Windows equivalent? You mentioned you are using Cygwin, if you are planning to use gcc/g++ etc. take a look at this tutorial
You can install them via Cygwin