There are two methods to do this,
Method 1
// Update the post-type post and then add your custom slug
add_action( 'init', 'update_default_post_slug', 1 );
function update_default_post_slug() {
register_post_type( 'post', array(
'labels' => array(
'name_admin_bar' => _x( 'Post', 'add new on admin bar' ),
),
'public' => true,
'_builtin' => false,
'_edit_link' => 'post.php?post=%d',
'capability_type' => 'post',
'map_meta_cap' => true,
'hierarchical' => false,
'rewrite' => array( 'slug' => 'blogs' ),
'query_var' => false,
'supports' => array( 'title', 'editor', 'author', 'thumbnail', 'excerpt', 'trackbacks', 'custom-fields', 'comments', 'revisions', 'post-formats' ),
) );
}
Method 2
Check this: Different permalink structure for blog posts than pages in Wordpress?
I hope this helps.