no idea about Snap but for Docker it is not trivial but doable using traefik reading docs for a while and try and error few times… you will find good documented traefik setup for docker-compose here (and collabora on top):
I don’t think you want a stranger setup your “secure” family server - without knowing what and why the stranger did… if you still want feel free to negotiate with people replied here, some of them are frequent posters in the forum which is sort of good sign…