Journal note or similar concepts exists in other apps. A journal note is nothing but a note titled with the current date that lies inside a special notebook that is split by months.
It could work like this
There is a special journal note, like todo, and note
User creates a new journal note
New note titled with the current date is created
It is put under (referencing today) Journal -> 2020 - > January -> 27
This is nothing but a special macro type behavior which creates necessary folder structure based on the current date.
I’m honestly not sure. I haven’t messed with Templates directly yet, but if someone hasn’t done what your requesting (I’d search just in case), this community seems pretty open to users creating their own workarounds and extra tools to make using Joplin so much more enjoyable.