You can override that template file at app/design/frontend/<Theme Vendor>/<Theme Name>/Bodak_CheckoutCustomForm/view/frontend/templates/order/view/custom_fields.phtml
. This is a better approach than editing the file directly as your changes will be overwritten if you ever decide to update this module.
As for the file:
<?php
/** @var Bodak\CheckoutCustomForm\Block\Order\CustomFields $block */
/** @var Bodak\CheckoutCustomForm\Model\Data\CustomFields $customFields */
$customFields = $block->getCustomFields($block->getOrder());
?>
<?php if($customFields): ?>
<div class="block block-order-details-view">
<div class="block-content">
<div class="box">
<strong class="box-title"><span><?php /* @escapeNotVerified */ echo __('Other information') ?></span></strong>
<div class="box-content">
<strong><?php /* @escapeNotVerified */ echo __('Buyer') ?>:</strong>
<?php echo $this->escapeHtml($customFields->getCheckoutBuyerName()); ?><br>
<strong><?php /* @escapeNotVerified */ echo __('Buyer email address') ?>:</strong>
<?php echo $this->escapeHtml($customFields->getCheckoutBuyerEmail()); ?><br>
<strong><?php /* @escapeNotVerified */ echo __('Purchase order no.') ?>:</strong>
<?php echo $this->escapeHtml($customFields->getCheckoutPurchaseOrderNo()); ?><br>
<strong><?php /* @escapeNotVerified */ echo __('Goods mark') ?>:</strong>
<?php echo $this->escapeHtml($customFields->getCheckoutGoodsMark()); ?>
</div>
</div>
<div class="box">
<strong class="box-title"><span><?php /* @escapeNotVerified */ echo __('Comment') ?></span></strong>
<div class="box-content" style="margin-bottom: 20px"> <?php /*Just add your CSS inline to the specific container you want to add spacing below.*/ ?>
<?php echo nl2br($this->escapeHtml($customFields->getCheckoutComment())); ?>
</div>
</div>
</div>
</div>
<?php endif; ?>
If you can post your updated code here so I can see it, I'll show you exactly what to change.