JSFiddle - React, Tailwind, and code Playground

HTML

<select name="bedrooms" id="bedrooms">
    <option value="0" selected>Choose One:</option>
    <option value="1">1 bed+</option>
    <option value="2">2 beds+</option>
    <option value="3">3 beds+</option>
</select>

<div id="resultsDiv"></div>

JavaScript

$('#bedrooms').change(function() {
    var beds = $(this).val();
    alert('Minimum beds: ' + beds);

	$.ajax({
		type: "POST",
		url: "somephpfilename.php",
		data: 'num_beds=' + beds,
		success: function(recd){
			$('#resultsDiv').html(recd);
		} //END ajax success fn
	}); //END ajax code block

}); //END select.change fn

/************************************************************
//  Save the below code into a file called:  somephpfilename.php

<?php
	$min_beds = $_POST['num_beds'];
	$query = "SELECT * IN `yourtablename` WHERE `cp_bedrooms` > '$min_beds' ORDER BY `cp_bedrooms`";
	$results = mysql_query($query) or die(mysql_error());

	$out = '
		<table id="foundApts">
			<tr>
				<th>Num Beds</th>
				<th>Address</th>
				<th>Contact Phone</th>
				<th>Rent</th>
			</tr>
		';

	while ($row = mysql_fetch_assoc($results){
		$out .= '
			<tr>
				<td>' .$row['cp_bedrooms']. '</td>
				<td>' .$row['address_field_name']. '</td>
				<td>' .$row['phonenum_field_name']. '</td>
				<td>' .$row['rentprice_field_name']. '</td>
			</tr>
		';
	}

	$out .= '</table>';

	echo $out;
?>

*********************************************************************/