Figure out my account creation date on Obsidian. I’m also trying to figure out the creation dates of my first notes. Perhaps this is possible using Dataview?
To find your oldest notes, go to Search and type /, then sort the results by creation date.
For your Obsidian account, log into it and I believe there’s a section where you can see your payments. If you have an account but haven’t paid for anything, you could check your email for whatever message(s) it sent when you created the account.