Install instructions for CODA itself are provided in the INSTALL file. You are mixing up installation from source from github with installation via conda. So please read the documentation carefully.
Assuming you are using the conda installation of CODA, then just put the AEOLUS .codadef file in your conda environment in the share/coda/definitions sub-directory. This way CODA will automatically find it.
The alternative is to put the .codadef somewhere else and point to it with a CODA_DEFINITION environment variable. Instructions for this can also be found in the documentation.