This project depends on Plugin SDK (https://github.com/DK22Pac/plugin-sdk). Using SDK's installer results in creation of PLUGIN_SDK_DIR envinroment variable in operating system. If installer is not used then please manually enter path to the sdk directory in setup_env.bat. If GTA SA is installed in different than default location please open setup_env.bat file and configure correct path. Run setup_env.bat to setup required envinroment variables.
After opening project solution in Visual Studio it should be possible to build as well as debug CLEO in game.