From a contact considering naturalisation, but who is below the cut-off age for military service or alternative civilian service (Zivildienst), I have received some information about civilian service. He has enquired whether whether teaching jobs can be considered as performing alternative civilian service, since many kindergartens use the services of Zivildiener (our kindergarten is one such example).
Unfortunately it can’t. Furthermore, unless the school(s) you teach at keep(s) you nominally on the staff lists for a couple of hours, you may not be able to retain your position at the school, due to the fact the Zivildienst is for the equivalent of a full-time position. The duration of Zivildienst is nine months, although there is a possibility to voluntarily extend it for a further three months. In this case the extra months are paid better than the normal Zivildienst pay.
The monthly pay for a Zivildiener as of 01.01.2020 is EUR 346.70 per month. However there is Verpflegungsgeld, to ensure that you have enough money for food, if Naturalverpflegung (i.e. meals provided is not offered). Naturalverpflegung consists of breakfast and one hot meal and one cold meal (with the hot meal as either lunch or dinner).
In some cases you are provided with accommodation too (i.e. residential /live-in jobs) on otherwise you can apply for financial assistance towards accommodation costs. In cases of financial support being required, this extends to spouses (i.e. by marriage or a civil partnership) as well as children, but not say a girlfriend/boyfriend.
Further information in German: https://www.zivildienst.gv.at/103/start.aspx
Note: h/t Friedrich Bruckner for reminding me that employers are obliged to keep your old job open for you for up to one month after the end of Zivildienst (and military service).