Here is how the lessons are organized and stored. I want to share my system for other teachers or self-directed learners. It has worked well for over eight years, for hundreds of learners. Thank you, Google!
In the image below, you can see all the Googledocs for one learner go into a folder, by year.
And actually, within each year, it saves times to divide the year into two sub-categories: 2020 July to Dec and 2020 Jan to July. The student can keep things organized in the same way on their end. Helping people be organized from the beginning is a valued service.
Each session has its own Googledoc, and I put memorable keywords into the title to help remember the conversations from that session. I also track the package number (package #6 in this case) and the lesson number within the package (this student gets packages of 10 sessions at one time).
The session template GoogleDoc that I use for every session is here.