For adding new Custom Post Type go to Appearance > Customize > Add Post Type then click on Add button and fill post type name, example movies
PS. Its better if you add post type name with prefix example cz_movies, in this case you will not get any conflict between plugins.
After adding new post type Save Customizer and Refresh page. Now you should see your post type panel in customizer, Go to it and you can change slugs, archive title, category slug, etc. If you want to change them do it then save customizer and exit from it.
Final step go to Dashboard > Settings > Permalinks and once Save it to rewrite WordPress permalinks structure. This will fix any error 404 on you site.