Making some kind of forms (at least experimenting with it) and I need help...

I am experimenting with the making of forms over html, but lets say, my knowledge of html is minimal, and so what I made was creating a new page on my test forum, then I edited the html there,

But I cannot post the thread without the Title and the message. I am stuck at the moment.

I need to set the thread's title to: "Minecraft Whitelist Aplication for <username>"
But I don't know how...

Anyone could help me on this?