[Not a teacher]Are these sentences correct with the given meanings:
1-I will either not watch the match or go to the movies.
(I will do one of the two but not both.)
Correct as far as I can tell, however it is a little unnatural to say you either won't do something or you will do something else.
2-I will either not the match or the movie.
(I will watch one of the two but not both.)
This is incorrect, you do not have a main verb for the auxiliary "will" not is there one implied – for which you need more than a related statment further up in the text and no object, e.g.r
"...and remember to wash the dishes when you're done!"
"I will [remember/wash the dishes]!"
3-I will either not talk to Dean or to Mark.
(I will talk to one of them but not to both.)
This doesn't make sense. What is being said here is you won't talk to either of them – with an either thrown into the sentence unnecessarily. If you want to say "I will talk to one but not both", you would say "I will talk to either Dean or Mark."