I have an i5 computer with a 770 nvidia graphics card and 8 gb of ram and 1TB ssd. I installed the MGSO mod and have been trying to play the game. I hit e to bring up my weapon and hold and release the left mouse button, but it doesn't move. I've tried to use the lockpick, but I can't get the hand to move even if I swing the mouse back and forth. That only effects the look. Any suggestions?

To attack in Morrowind (and in older TES games), you need to hold the mouse down and move the mouse in a swinging motion. Also, don't be surprised if the majority of your attacks miss, at least at first.

Also, you are not supposed to use a lockpick as a weapon; there's apparently a glitch in some versions that lets you do this, but it isn't as easy as just equipping it and swinging it.

My controls said E to ready weapon. And it did bring up my weapon. It just wouldn't work when I tried to attack. I went back and looked at the controls list and reset it to default and now it is F to ready weapon and it is now working. I don't know how the control keys were changed like that. I didn't try to change them. Anyway, thanks so much and now I am playing and winning a few fights. Yay!

You're welcome.
But watch out for further potentially controls-related problems: the "E" key is used for jumping, by default, and will definitely not bring up your weapon. I'd consider to reset the controls to default (which you can do from the options somewhere, if I remember correctly. From there you can make the changes you want, if you are unhappy with the defaults.