To get the total amount of items in a foreach loop:

$looped_date = get_field('looped_data');
$total_items = count($looped_data); 
echo $total_items;

Get the total amount of items from a custom $wp_query loop:

$custom_query = new WP_Query($args);  
$total_items = $custom_query->found_posts;
echo $total_items;

Number each item within a $wp_query and foreach loop:

$i = 1; // add this before the foreach
echo $i++; // add this once within the loop

Number each item within repeater (ACF). Learn more.

echo get_row_index(); // add this once within the row