Bit confused about what you're looking for. If you're just SSH/VNC ing into devices on the same local network, then you can simply use their local IP address, which you can find with a command like ip addr
and will rarely change, or their hostname if your network is configured properly. There are several GUIs that can remember connection info for you, so you likely will only need it once. It's also quite easy to scan the local network for SSH servers if you have nmap (nmap -p22 <your ip address range, e.g. 192.168.0.1/24>
). If you need to connect to a device on your home network from a different network, any VPN software can achieve that. I'm not aware of any remote desktop solution that doesn't require a network connection, but your network doesn't necessarily need to be connected to the Internet.
Are you looking for a GUI that combines all those things?
What is a "must have" depends on your use case, personal preferences, and the shortcomings of your distro's default configuration (I've never used Cachy so I don't know what's missing).
For myself, I usually end up installing VLC and Strawberry Media Player, since the media players most distros come with aren't as good. On non-GNOME distros I tend to install GNOME Disks as it's the least painful to use of the GUI partitioning tools I have used. My preferred rich text format is Markdown, for which I use ghostwriter. I also usually install a few FOSS games to pass the time with - my favorites are Freedoom, SuperTux, SuperTuxKart, and Xonotic - and RetroArch for emulation.