My tables:

    dzialki
    +--------------+-------------+------+-----+---------+----------------+
    | Field        | Type        | Null | Key | Default | Extra          |
    +--------------+-------------+------+-----+---------+----------------+
    | id           | int(11)     | NO   | PRI | NULL    | auto_increment |
    | nazwa        | varchar(50) | NO   |     | NULL    |                |
    | powierzchnia | varchar(50) | NO   |     | NULL    |                |
    | state        | tinyint(1)  | NO   |     | 0       |                |
    +--------------+-------------+------+-----+---------+----------------+
        
and
 

    dane
    +--------------+--------------+------+-----+---------+----------------+
    | Field        | Type         | Null | Key | Default | Extra          |
    +--------------+--------------+------+-----+---------+----------------+
    | id           | int(11)      | NO   | PRI | NULL    | auto_increment |
    | stawka       | decimal(9,2) | NO   |     | NULL    |                |
    | partycypacja | decimal(9,2) | NO   |     | NULL    |                |
    | skladka      | decimal(9,2) | NO   |     | NULL    |                |
    | woda         | decimal(9,2) | NO   |     | NULL    |                |
    | smieci       | decimal(9,2) | NO   |     | NULL    |                |
    | energia      | decimal(9,2) | NO   |     | NULL    |                |
    | inwestycyjna | decimal(9,2) | NO   |     | NULL    |                |
    +--------------+--------------+------+-----+---------+----------------+

---

Sorry for the English, I use google translator.  I built a component for J4 based on 2 tables (as CRUD) on https://www.component-creator.com. I am trying to make a module based on Ajax examples and it is not working out. On my site https://rod-lubocza.pl/blog/finanse is what I mean in html + js. I am not familiar with php, js and ajax. I write code based on examples found on the web.

As for the module, I have this code in the tmpl/default.php file:

    <?php
    /**
     * @package     J4.Module
     * @subpackage  mod_kalkulator
     *
     * @copyright   Copyright (C) 2022 ROD Lubocza Wszystkie prawa zastrzeżone.
     * @license     GNU/GPLv3 http://www.gnu.org/licenses/gpl-3.0.html
     */
    
    defined('_JEXEC') or die;
    use Joomla\CMS\Language\Text;
    use Joomla\CMS\HTML\HTMLHelper;
    use Joomla\CMS\Factory;
    
    $db = Factory::getDbo();
    $query = $db->getQuery(true);
    $query->select($db->quoteName(array('id', 'nazwa', 'powierzchnia', 'status')))
    	->from($db->quoteName('#__kalk_dzialki'))
    	->where($db->quoteName('status') . ' = ' . $db->quote(1))
    	->order($db->quoteName('id') . ' ASC');
    $db->setQuery($query);
    //echo $db->replacePrefix((string) $query);
    //$results = $db->loadAssocList();
    $results = $db->loadObjectList();
    ?>
    
    <div class="kalkulator">
    	<div id="kalk" class="mb-3">
    		<form action="" method="post">
    			<select id="select" class="form-select" aria-label="Default select" autocomplete="off"> 
    				<option value="" hidden selected="selected">Wybierz działkę</option>
    				<?php foreach ($results as $row){ ?>
    				<option value="<?php echo $row->id; ?>"><?php echo $row->nazwa; ?></option>   
    				<?php }?>
    			</select>
    		</form>
    	</div>
    	<table class="table">
    		<tbody>
    			<tr class="table-success"><td class="col-6 fw-bold">Numer działki</td><td class="col-3"></td><td class="col-3 text-center fw-bold"><div id="kalnazwa"></div></td></tr>
    			<tr><td>Powierzchnia:</td><td class="col-3 text-center">m2</td><td class="col-3 text-end"><div id="kalpowierzchnia"></div></td></tr>
    			<tr><td class="col-6">Stawka opłaty ogrodowej</td><td class="col-3 text-center">0.69 za m2</td><td class="col-3 text-end"><?php echo $stawka; ?></div></td></tr>
    			<tr><td class="col-6">Partycypacja</td><td class="col-3 text-center">0.09 za m2</td><td class="col-3 text-end"><div id="kalpartycypacja"></div></td></tr>
    			<tr><td class="col-6">Składka członkowska</td><td class="col-3 text-center">od działki</td><td class="col-3 text-end"><div id="kalskladka"></div></td></tr>
    			<tr><td class="col-6">Opłata za wodę</td><td class="col-3 text-center">od działki</td><td class="col-3 text-end"><div id="kalwoda"></div></td></tr>
    			<tr><td class="col-6">Opłata za śmieci</td><td class="col-3 text-center">od działki</td><td class="col-3 text-end"><div id="kalsmieci"></div></td></tr>
    			<tr><td class="col-6">Opłata energetyczna</td><td class="col-3 text-center">od działki</td><td class="col-3 text-end"><div id="kalenergia"></div></td></tr>
    			<tr><td class="col-6">Opłata inwestycyjna</td><td class="col-3 text-center">od działki</td><td class="col-3 text-end"><div id="kalinwestycyjna"></div></td></tr>
    			<tr class="table-success"><td class="col-6 fw-bold">Do zapłaty</td><td class="col-3 text-center"></td><td class="col-3 text-end fw-bold"><div id="kaldozaplaty"></div></td></tr>
    		</tbody>			
    	</table>   
    </div>

I want to return data from 2 tables mysql to a table html using the select field. Can I ask for help?