When you launch Marrowind do you always get this,

"One or more files could not find the correct version of the files .... etc"

Yes, I know it is this mod for it was the only one I added today (it is my second mod ever adding to Morrowind) my question is is this ok to still play or did i do something wrong?

Technically, this is a harmless warning.
But it can easily be fixed by Updating the Masters of the esp mentioned in the warning.
You can do this quickly in Wrye Mash. (the esp will appear Yellow, but you want it to be Green)

In Mash:
Highlight the esp in question.
Click on the Box (listing the Masters) in the bottom right hand section.
It will ask "Edit/Update the masters list? etc"
Click OK.

The warning is caused when you use any mod (not just Multimark) that was made with a different version of Morrowind than the one you have installed.
This is common and normal. Mods are made with the many different versions of the game that exist, but your game is confused as to why everything isn't the same version as your install.