Sort posts based on an acf field called fecha value return longtext ‘20240517’

You should be able to order your posts by adding the following to your main args:

'meta_key' => 'date',
'orderby' => 'meta_value_num',
'order' => 'ASC',

Example:

$args_post = array (
    'post_type' => 'post',
    'posts_per_page' => -1,
    'fields' => 'ids',
    'meta_key' => 'date',
    'orderby' => 'meta_value_num',
    'order' => 'ASC',
    'tax_query' => array(
        array(
            'taxonomy' => 'tipo-de-contenido',
            'terms' => 'actividades-y-talleres',
            'field' => 'slug',
            'operator' => 'IN'
        )
    ),
);

You mentioned in your question that the field is named “acf date”, in my code I’m assuming the field name is actually just “date” as the former wouldn’t make much sense. If that’s not the case be sure to change ‘date’ to your actual field name.