Configuring automatic login shouldn't be difficult. Here are instructions on Ubuntu (should work on any GNOME system), and here's how to do it with pretty much any KDE system. This is a feature of desktop managers (like gdm or sddm), not desktop environments (like GNOME or KDE), so if neither works for you, you're probably using a different one. If that's the case, reply with your distro and as much info as you can provide.

That said, what exactly is the problem you're trying to solve? It's usually a lot easier to login remotely using SSH instead of remote desktop, and then use console commands to do whatever you need. To login with SSH:

ssh <user>@<IP address>

So if your username is tux and your IP is 1.2.3.4:

ssh tux@1.2.3.4

And then if you want to reboot:

sudo reboot

And if you want to shutdown:

sudo shutdown -h now

I use an app on my phone to login, so I can get it done while sitting on the toilet in like 10s (I use it to unlock my computer so my kids can use it). If you're accessing from your computer and just need to run a single command, provide it after the command in quotes (note, sudo commands won't prompt for a password and will just fail).

I have three ideas: First, you could switch the desktop environment to one of the ones that has a GUI settings tool to set passwordless automatic sign in. I think Gnome 3 on Ubuntu, and Mate Desktop on Linux Mint have that feature. There are probably others.

Second, you could switch your display manager to "nodm". The display manager is the thing that runs the X server or Wayland, and it starts the greeter (the greeter is the program that shows the login screen). nodm is a special display manager that doesn't use a greeter or ask for a password. It immediately starts the session using the username and desktop environment specified in its configuration file.

I use nodm for my HTPC and it works very well. The only downside is that you have to edit its configuration file, /etc/default/nodm , using a text editor. I'm not aware of any GUI configuration tool for it. However, it's pretty easy to configure.

Third, you could abandon all display managers, and start the session manually, either from a shell script, or over SSH. This is a little more complex. You will probably want to get comfortable with SSH before trying this (SSH is the command-line analog of remote desktop).

I think the first thing is actually recommend is enabling a daemon that launches Plex at boot without login. sudo systemctl enable plexmediaserver For something like a Minecraft server I'd recommend reading up on the setup process. (It's a fair bit to summarize)

If the application doesn't come with a systemd service I'd recommend making a cron. They're scary looking but actually pretty easy to use, I use it for automating maintenance on my server.

It may feel counter intuitive but Linux servers don't really need a desktop to manage them so most the tools don't really come with graphical apps. If you want an interface to check on things I'd recommend installing and using cockpit web based graphical interface.

If you want to do it proper on a systemd system make a systemd.service it's not as easy to learn but you get extra tools to manage it.

I've heard there's a lot of work that has been done in kde and gnome to get rdp (remote desktop protocol) with remote login.

I hope this helps! If not, almost everything can be done through the terminal and ssh(secure shell) makes that process really easy. I installed and setup my Linux laptop and my server that way.

If you just want to transfer files there is sshfs(secure shell file system) and the ability to go to your file browser and type in an sftp(secure file transfer protocol) address. In kde dolphin for example you select network and type in the bar sftp://(IP address or hostname)@(user):(working directory). Make sure you have sshfs installed on both machines and sshd enabled on at least the system you want to access.

What about SSHing into it?

I have a pi5 at work (upgraded this year) that I use to administer my work network from home. I use ubutnu mate with xrdp for the desktop. Works great, even the sound works. No monitor and even if you hooked one up it would just show a login prompt.

Yeah I also haven't found a good alternative for a windows management host for RDP. I use my last remaining windows box as an "admin host" and the Linux alternative to this would be vnc or xrdp, both of which have their issues (no dynamic resize, clipboard issues, session restore issues)... I've also tried x2go recently which is closer but still not as slick/simple as a windows RDP session.

Get a virtual hdmi dummy plug. A very cheap and easy fix. Because the machine now thinks a screen is attached it will create a desktop environment you can remote in to.