Can’t Add Pagination

If you want to show only 5 posts you should set posts_per_page to 5.
And by setting paged parameter to any number you want, you can query posts in a specific page.
For example if you want to get posts 6 to 10 you should do:

$args = array(
    'post_type'      => 'project',
    'posts_per_page' => 5,
    'paged'          => 2 
);