Looking for specific software in Debian repos

I'm looking for specific types of software available in Debian repositories.
I don't want Flatpaks, App images, or to grab .deb files from any old website.
I plan on enabling a Debian 12 Bookworm environment on my HP Chromebook 14 and then getting some Linux apps only via things like Apt (or Synaptic).

Here's what I'm looking for:

1. A browser... other than Chromium or Firefox ESR (Extended Support Release)... unless those are some of the best options.
2. A calendar (with search)
3. An IDE
4. A markdown editor (I know I can edit markdown files in an IDE, but I'd like to be able to see the output.)

The most important item is the browser. I'm writing this in the Android version of Firefox on chromeOS which isn't very fun for me to use.