For general linux applications, learning your way around tmux sooner rather than later is pretty key. Emacs is quite handy especially if you find things like org mode useful in your day to day (or others -- there are definitely AI plugins for it, as well as, well, everything else). OpenSSH is pretty key for remote access (as well as tunneling into your services like a Bitcoin node, without needing to expose it to the public Internet). KeePassXC will very nicely replace your password management, and can sync with mobile clients via SSH so you've got access to it everywhere. If you have a music collection you want access to, MPD is an old standby of mine. I use TT-RSS for handling my RSS subscriptions, as it has a nice android client as well (and sets up a web server for viewing anywhere) ensuring RSS client state is synced wherever I use it from.

Definitely a fan of i3 as a window manager, though that may not be your go to if you're new to Linux, as it is almost entirely hotkey driven.