WordPress : Form data is not displaying via echo - php

Question

I have created a form to which I am passing the data. When I try to echo the data it shows couple of errors saying that index is undefined.
<?php /* Template Name: Dummy Practice Page*/?>
<div id="main-content" class="main-content">
<div class="main-content-inner">
<form method='post' enctype='multipart/form-data'>
<input id="name" type="text" style="height:30px; width: 350px; " maxlength="5" placeholder="Name" required><br>
<input id="designation" type="text" style="height:30px; width: 350px; " maxlength="50" placeholder="Designation" required><br>
<input id="description" type="text" style="height:30px; width: 350px; " maxlength="1000" placeholder="Description" required><br>
<input id="pic" type="file" style="height:30px; width: 350px; "><br><br>
<input name="insert" type='submit' style="height:40px; width: 130px; padding:10px; color:dodgerblue; background-color:black; border-radius:20px; " name='Submit' value='Add Member' /><br><br>
</form>
</div>
</div>
<?php
if(isset($_POST['insert']))
{
echo $namevar = isset($_POST['name']);
echo $descriptionvar = isset($_POST['description']);
echo $designationvar = isset($_POST['designation']);
}
?>
Following are the errors:
Notice: Undefined index: name in C:\xampp\htdocs\wordpress\wp-content\themes\twentyfifteen-child\practicepage.php
Notice: Undefined index: description in C:\xampp\htdocs\wordpress\wp-content\themes\twentyfifteen-child\practicepage.php
Notice: Undefined index: designation in C:\xampp\htdocs\wordpress\wp-content\themes\twentyfifteen-child\practicepage.php

Answer 1

<form method='post' enctype='multipart/form-data'>
<input name="name" type="text" style="height:30px; width: 350px; " maxlength="5" placeholder="Name" required><br>
<input name="designation" type="text" style="height:30px; width: 350px; " maxlength="50" placeholder="Designation" required><br>
<input name="description" type="text" style="height:30px; width: 350px; " maxlength="1000" placeholder="Description" required><br>
<input id="pic" type="file" style="height:30px; width: 350px; "><br><br>
<input name="insert" type='submit' style="height:40px; width: 130px; padding:10px; color:dodgerblue; background-color:black; border-radius:20px;" value='Add Member' /><br><br>
</form>
<?php
if(isset($_POST['insert']))
{
echo $namevar = $_POST['name'];
echo $descriptionvar = $_POST['description'];
echo $designationvar = $_POST['designation'];
}
?>

Answer 2

The issue is with the names of input fields.
In PHP or any other programming language, You should use the input name="something" to get the input values.
You should give the name for each input fields.
For example,
<input name = "name" id="name" type="text" style="height:30px; width: 350px; " maxlength="5" placeholder="Name" required><br>

Answer 3

You cannot pass POST data to another page vie using ID.
You should give name to <input>
<input name="name">
<input name="description">
<input name="designation">
Edit
You are defining variables and echoing them same time
Change your code to:
<?php
if(isset($_POST["insert"])){
echo $_POST["name"];
echo $_POST["description"];
echo $_POST["designation"];
}?>