Startup problems login

This is rather complicated. I was having problem with RDP. When connecting there was a message about another user and did I want to connect. If I said yes it then said Waiting for [computer name]/Administrator to respond. About a minute later it would log in.
I spend several days trying to get rid of that and eventually this sort ofworked
click start
type netplwiz and press enter
untick "users must enter a username and password..."
click apply
Now my RDP session connects great.
But it I reboot the computer with the screen plugged in it now says
Administrator
The Username or password is incorrect. Try again.
OK

After clciking OK there's a password box and a Reset option.
There's also 4 names on the LH side at the bottom.
Administrator
myname
Win10
Administrator

Clicking the first Administrator works, also if I do nothing for about a minute the desktop appears.

Googling found this
to prevent it asking for a password when waking from sleep, go to settings -> accounts -> sign-in options
under "require sign-in" select Never.
But I cant do that as it tells me there is no password and I need one to continue.

I'm the only user and just want it to work with no prompts or passwords.
This PC is not on the net, and normally only used for rdp.

Now if I boot it without a screen RDP is okay... but with a screen RDP still repeats the "another user" and please wait message.
And on the remote screen is a prompt to allow the connection.
My win ver is Version 2004 (OS Build 19041.685), remote version is 1511 Build 10586.679

Hi Lance, done that but it still shows the prompts and the wait (if the remote machine is logged in)

My RDP session is now ok if there's no login (i.e. booted without a monitor).

That's part of the problem, I have no idea and can't remember passwords. Where possible I avoid them like the plague!
Nor can I figure out (at switch on) what a/c is in use. Until now I'd have thought there was only one.
However at the moment RDP is working and at bootup (with no monitor ), otherwise I can hit ok and wait 30-40 seconds. Not ideal but better than it was. I had thought about removing some but worried it might bugger things up completely. (Like no boot at all w/o password)