Need to Create USER with limited Access (1 post)

Hi,

I need to create a USER ( employee )
this USER can view only his Post category and own Post
this user can add post only in own category
edit / delete / add / own category post

but can’t edit his category name

when he login
in backend he can view only his post only
other thing will not be visible for this USER ( Employee )

i have created a USER through add new user section and assign As an ( Author )

but when this user logged in
this user can view not only his own post
but also he can see out few PLUGINS
i don’t wanna show him our plugins

when this USER ( employee ) logged in his account
he can see only his Post
nothing else

Please give me right solution for this

I am not a Programing expert