After Installing the module follow this steps.

Steps : Settings -> Technical -> User Interface -> Menu Items.

To hide the 'Translations' menu go to Menu Access Restriction and add a group.

Here you can see that Admin user is now not able to see Translations menu.

To restrict the Users & Companies menu for the users, add the users in the Restrict For Users.

Here we can see that Users & Companies menu is restricted for the users.

To hide the menus from the user you can also add the menus in the Restrict Menu.

Here you can see that the Users & Companies, Translations and Technical menus are restricted the particular user.

To make the fields readonly and invisible follow these steps.

Steps : Settings -> Technical -> Database structure -> Models.

Add the fields which you have to make readonly or invisible.

Here you can see that the fields Email and Phone are set as readonly and the field Tax is not visible in the view.

You can also have the options to Rewrite Options for the Many2one fields.

Here you can see that we are not able to create or edit the Country field.

Also we can hide Smart Buttons from the users.

Add the smart button field in the Fields Security.

Here you can see that the Invoices smart button is not visible.