Create Shortcode to display in post or pages

I'm completely lost in code as always so I'd rather ask before I spend hours with it.

Can i create a shortcode to display fields as gallery or whatever?
Images needs to use foreach to display it.

foreach ( $digall as $key => $value ) {

$image = RWMB_Image_Field::file_info( $value, ['size' => 'large'] );
 echo '<div class="swiper-slide"><img alt="" src="'. $image['url'] . '" /></div>';

}

But i need to create shortcode..

function digallery($atts) {
    $a = shortcode_atts( array(
        'posts_per_page' => '',
        'gellery_id'  =>  ''
    ), $atts );

$digalleries = rwmb_meta( 'digallery' );
$digall = $digalleries['gallimage'];// Illegal string offset 'gallimage'

$digallery = '';
$post_in = esc_attr($a['testimonial_id']);
$posts_per_page = esc_attr($a['posts_per_page']);

$post_artay = explode(',', $post_in);
$args = array(
    'post__in' => $post_artay,
    'posts_per_page' => $posts_per_page,
    'post_type'        => 'divart_gallery',
    'order_by' => 'post__in',
);

// the query
$the_query = new WP_Query( $args );

if ( $the_query->have_posts() ) :
while ( $the_query->have_posts() ) : $the_query->the_post();

$digallery.= RWMB_Image_Field::file_info( $value, ['size' => 'large'] ); // to loop ?

$digallery.= '<div class="title">'.get_the_title().'</div>';
$digallery.= '<div class="content">'.get_the_content().'</div>';
$digallery.='<div class="date">'.get_the_date().'</div>';
$digallery.='<div class="author">'.get_the_author().'</div>';

endwhile;
endif;
return $digallery;

}
add_shortcode('gallery', 'digallery' );

//and shortcode would by

[gallery posts_per_page="1" gellery_id="217"]

Would anything like that be possible?
Thank you