Great question! This may help for the starting/joining of the meeting: https://www.virtualizationhowto.com/2020/08/zoom-automatic-join-meeting-how-to/
VokoScreen has a scheduling function and it does allow you to monitor the sound card input, so am pretty sure you could login above, then record with Vokoscreen (assuming your are on Linux or Windows.
I use VokoscreenNG to record some my class lectures. It can record everything on the desktop, a specific window or a specified area. So, should suit your purposes OK.
If you go with the window option, it will only record that window even if you open other programs or even drag another program over the selected window.
If you only want webcam video: GNOME Cheese If you want a lightweight screen recorder with both screen video and webcam video: Vokoscreen (you can also use OBS if you know how to use it)