@ugnvs is right, SSSD is not needed in a home setup. One of the comments explains a lot:
It's not an error though. It's just logging that it didn't start sssd, which isn't an error for a user who doesn't need the enterprise integration that sssd provides. I realise that "start condition failed" might sound alarming, but that's the mechanism that's supposed to be used to avoid attempting to start a service when that service isn't required.
It seems that sssd can't do its job because it can't find its configuration files.
If you really want to start sssd , this should do the job:
sudo cp /usr/lib/x86_64-linux-gnu/sssd/conf/sssd.conf /etc/sssd/.
sudo chmod 600 /etc/sssd/sssd.conf
This gets the configfile from the directory where the package dropped it and puts in in the directory where sssd expects it to be.