Limiting Posts And Pagination

what is the full code of your template?

are you using a static home page based on a page template, or is that the index template?

what theme are you using?

if you are using a custom query, you will need to include the ‘paged’ parameter;
see https://codex.wordpress.org/Pagination

https://codex.wordpress.org/Pagination#Adding_the_.22paged.22_parameter_to_a_query (but do not use query_posts() )

if you are using the index template, please review https://codex.wordpress.org/Plugin_API/Action_Reference/pre_get_posts

adapt the code from https://codex.wordpress.org/Plugin_API/Action_Reference/pre_get_posts#Changing_the_number_of_posts_per_page.2C_by_post_type

example:

function different_home_pagesize( $query ) {
    if ( is_admin() || ! $query->is_main_query() )
        return;

    if ( is_home() ) {
        // Display only 3 post for the original blog archive
        $query->set( 'posts_per_page', 3 );
        return;
    }
}
add_action( 'pre_get_posts', 'different_home_pagesize', 1 );

and add