[Help]Creating a directory hierarchy? Plus Making Urls Case-Insensitive[HELP]

So... I need to know how I would make url pages like this,
www.example.com/
www.example.com/fruit/
www.example.com/fruit/orange
www.example.com/fruit/apple
www.example.com/fruit/pear
^Took that from Google btw
and how would I make urls case insensitive, currently it's like this
www.example.com/fruit.html
and then if you do,
www.example.com/FRUIT.html
it won't work.
I've tried googling, something with a 404.php file in public_html and then adding a line to .htacess, but no luck.