To start work with your Fortran project use
New > Project from existing sources action. In CLion it is also possible to load
CMake based projects, see instruction. Example of Fortran project build with
CMake can be found here. Using
CMake project in CLion allows you to compile, run and debug(via GDB) project from the IDE. Fortran run configuration should be used for debugging.
Fortran source files might be in two forms: free form and fixed form. For now some features are available only for free form. The plugin differs source forms by the file extension.
.for files are handled as fixed form source files while
.f08 files are in free source form. One can easily change this settings. Please, visit File Types Help for further detail.