With what parameters to record video lectures?

Question

Video

You need to record a video lecture. The lecturer in the frame will walk in front of the blackboard and write on it with a marker.
The issue with the sound was solved by purchasing the Boya BY-WM4 radio loop. We will record video from the xiaomi mi 10 lite phone on a tripod. After editing in Sony Vegas 13, the video will be uploaded to Youtube.
The Filmic pro video recording software on your phone allows you to set the resolution (SD 540p, HD 720p, HD 1080p), aspect ratio (16:9, 3:2, 4:3, etc.) and frame rate 24, 25, 30.

Say, please, what resolution, aspect ratio and frequency should be set so that the quality meets modern requirements and viewing features on youtube? With a reasonable file size.

UPD: For example, I took an arbitrary two-hour lecture on YouTube.
Through savefrom, it is downloaded in 720p resolution and has a size of 320 mb. Youtube shows this lecture incl. in 1080p, and in this quality it looks better. How many times should a 1080p video weigh more than a 720p video? Three times? That is, 2 hours should weigh a gigabyte? Ok I agree.
But in 1080p filmic pro writes a video weighing 155 mb / min! This is a lot. Or am I not understanding something?

UPD2: the radio loop failed, in the middle of the recording it began to make noise and buzz.
We write with a wire loop, even though it interferes with the lecturer. We will buy a voice recorder, hang it on our belt, and record the sound separately.