Merry and I used to play the MUD games a lot at one time and they are a lot of fun.
We have an introduction page here and here you will find a client to make playing it much easier.
That one is good, but hard to set up so here is a more straightforward one called AlClient. Its meant for Ashavars Legacy, but that's ok. It will work just fine on our MUD.
If there is any interest we will post more info about MUDs in general and MysticalMud in particular
Note that Alclient is now v2.19 so download it again. Installing it over the old one will not wipe your config file.
You have your Client program and given it the address.
MysticalMUD.com
Port 5000
Now the MUD asks you for character name and password. The name can be anything that fits a 'Sword & Sourcery' theme and should be original. So you can't be Lancealot or Whitney Houston. 
I see you can have a middle and last name now. I didn't bother for the moment.
Choosing Race and Class is quite important, but at this stage you may as well just try one out and see how you like it. You can always start another char later.
It asks about the display. I couldn't remember so I got that wrong, but you can put it right once you begin. I think it should be (for most people & clients)
Display normal
Color normal
resize 30 (depending on screen size)
If you want your stats to display along the bottom type Display on its own to see the options. So Display H shows your HP (hitpoints) which go down if you are losing a fight.
All that is quicker to do then it is to say and then you are in the Mud and ready to explore.
Don't choose PK until you have learned how it all works. PK means you can kill and be killed by other players. There are complex rules and its not for the beginner. If you don't chose it then you just fight the game characters which is better anyway.