Input Form database styling

Input Form database styling

So I am trying to create form that user will use to add data to database
here is example:
<form method="get" action="">
English Word: <input name='word'>
</form>
<?php
$word=$_GET['word'];
$sql="INSERT INTO engdic (`EnglishWord`) VALUES ('<li><b>$word</b></li>')";
?>
So the idea is costumer will input just plain text and threw php it will
add html tags to that text that will apply specific styling. What I am
really looking is for good example or any idea how to do it correctly
officient etc. I will have about 20 different another example field for
url for video so instead of costumer add link , I want that costumer only
add link.html and rest is added by js or php etc . Sorry for my bad
English and I hope the my idea is clear. Thank you for your time.