You would have to install google services in waydroid as well. There is as far as i know no simple solution with google services preinstalled.
However, you can install microG. This enables google services in sailfishOS.
For a tutorial look here: https://forum.sailfishos.org/t/microg-on-sfos-4
There is even a video.
For the su (or devel-su) command you need to enable developer mode in the settings and use the password from there. The su commands are for Switch User and switches to the root user. This user has permissions to do everything and can destroy things (and repair them). Feel free to ask questions here. We’re happy to help 