PHP Simple Form Validation

Question

I want a form validation like the following.

1. Name: [required, min length: 2, max length: 255]
2. Email: [required, min length: 3, max length: 255, valid email format]
3. Date of Birth: [optional, format: dd/mm/yyyy]

My code so far:

index.php

<form method="post" action="confirm.php">
Name:<input type="text" name="name" />
email:<input type="text" name="email" />
DOB:<input type="date" name="dob" />
<input type="submit" value="submit" />
</form>

and

confirm.php

<?php

$name = $_POST['$name'];
$email = $_POST['$email'];
$dob = $_POST['$dob'];

$namelen = strlen($email);
$emaillen = strlen($email);
$max = 255;
$minname = 2;
$minemail = 3;

if($namelen<$minname){
    echo"name must be at least 2 characters";
}
elseif($namelen>$max){
    echo"name must be less than 255 characters";
}

if(empty($name)){
    echo"name is required";
}
else{
    continue;
}

if($emaillen<$minemail){
    echo"email must be at least 3 characters";
}
elseif($emaillen>$max){
    echo"email must be less than 255 characters";
}

if(filter_var($email, FILTER_VALIDATE_EMAIL)){
    continue;
}
else{
    echo"invalid email";
}

if(empty($email)){
    echo"email cannot be left empty";
}
else{
    continue;
}

?>

Can someone please help me do this?