I use two (simple) methods for this, both in my daily note.
- I’ll mention that I “Talked to [[Person]] about [[Topic]]”
- If a meeting happens that needs more notes/research, etc, I’ll link to a meeting note titled [[2022-02-07-Meeting Name]], then link participants, topics, resources, or projects to THAT note. This meeting note stays in the same folder location as my daily notes.
I like that I can simply go to a person or topic note and look in the backlinks to immediately see dates I talked to them, and usually there’s enough context to know what I talked to them about. Note - I don’t always link to a topic unless it’s related to a larger concept or project specifically.
The other benefit is that I use no metadata in my vault for “normal” notes, like dailies. I do use it sparingly on research notes and to mine things like birthdates and anniversaries, but I really find that having to enter it all the time is… really, really distracting.
I’m sure you’ll find many methods that use dataview or complex queries, but I find I don’t need anything complicated for this. YMMV. I personally leave dataview to more complex data mining.
In short: Links and backlinks can be really powerful, and are often overlooked and underused as a fast way to tie things together.
I’ll be interested to see other approaches as well, but for now I’m sticking with what works for me. I’m more apt to use it that way 
!