Included in the Editor Pack are several template avatar models that can be used when making new content. These can be found in Assets/SpacePack/Artist Project/Avatar Art/Templates. It is recommended to make a copy of the model to import into your program of choice in order to avoid accidentally saving over it.
Until further notice, the 2015 or 2017 templates should be used, as the 2019 avatar models are unfinished.