On https://hangouts.google.com or https://gmail.com
Double click the contact to report to open the chat window
Click the gear button
Click the Block & report button
Check the Also report checkbox
Older related Q&A (they don't mentions the above steps)
How do I report spam/scam attempts in Hangouts?
How do I report scammers on Google Hangouts?
Yes, but not using Meet and the natural language processing it provides directly.
Even if you record a meeting, captions are not recorded and don't appear when you play the recording.
What you can do is record the meeting, download that recording, and then use some third party app to create a full transcript from that video. For example, you could upload to ...