On the "conversion complete" bit: if you migrated your stuff from, say, Notion, did you move all of it to Obsidian or do you still use Notion for some things?
I moved from Notion after I made a database of about 40 items and Notion became super slow for me. I manually moved my information over and didn't finish doing that. I don't use Notion anymore, except to transfer things that are still hanging out there. (They are not things I expect to need to reference frequently, hence being able to not use Notion and leave them untransferred. However, I still want to transfer them because I might need to at some point, and want it in one place instead of having to run back to Notion.)
I used to use Google Docs for my academic notes and have been writing new ones in Obsidian. I transferred a few docs manually, but the rest are, like with Notion, untransferred and still in Google Docs. Since I still do use Docs for anything collaborative, since the workspace is still something I use, it is still convenient for me to just search for my old academic notes in Docs. Would like to eventually transfer to Obsidian. I originally wanted Notion to be my place for everything, and to move all my Docs information to Notion. Now that I've abandoned Notion for Obsidian, my goal to move my Docs information has changed to moving it to Obsidian.
There are probably plugins to transfer from these places to Obsidian, or at least some script to make .md files out of Notion and Docs things. Part of why I don't do this is because when I transfer, I also like to clean up the information. Investigate things that were written down hastily that I no longer understand, make that stream-of-consciousness more comprehensible, remove information or to-do-later things that are no longer relevant…
For dummies like me, Cornell NTS is just Cornell Note Taking System, which seems to include but is not exactly the same thing as Cornell Notes.
It really revolutionized my learning. Taking notes in this way necessarily generates a study guide which can easily be turned into flash cards.