Comment Form Styling

Hi all,

After searching all day, I still can’t find an appropriate tutorial on this. Can anyone help me?

Basically at the moment I have a really ugly comment form on my website, https://astrozombies.net84.net.

What I’d really like is a nice neat little one that looks something like this: https://webdeveloperplus.com/wp-content/uploads/2009/09/WordPress-Comment-Form.png

But I have no idea how to even begin to change any of it. HELP! PLEASE!

Thank you in advance to anyone who comes to my rescue here.