While I'm a vi/vim/ed guy rather than an Emacs guy, I'll gladly cheer you on in your #plaintext & #CLI adventures.
For my personal finances, I use `ledger` (https://ledger-cli.org/) for #plaintextaccounting and I know it has some Emacs scripts available to make it easier.
For calendaring, I'm a big advocate for using `remind` (https://dianne.skoll.ca/projects/remind/). It's incredibly powerful, and as a CLI tool, pipes well to other utilities.
I don't know if you have a preferred mail program—whether that's Gmail in a web-browser or Thunderbird for a rich-client, or a command-line mail program like mutt/neomutt or even classic `mail` (or its souped up cousin `s-nail`).
There's a "blinux" (blind Linux users) mailing list if that's your jam. I think it's at http://leb.net/blinux/blinux-list.html I'm not blind/VI myself, but I lurk on the list and try to answer the occasional question as I have opportunity, and have an appreciation of keeping CLI tools accessible.
Anyways, here's cheering you on.