how to delete a topic?

If there are already replies, you cannot delete it.

Although you can send a private message to a mod, and they can delete it for you.

Use the report button in the first post and request a deletion

OR

PM the Moderators with a link to the topic:
Tsujoi - https://www.fakku.net/profile.php?mode=viewprofile&u=1344
Gambler - https://www.fakku.net/profile.php?mode=viewprofile&u=9051
Waar - https://www.fakku.net/profile.php?mode=viewprofile&u=31013
Teclo - https://www.fakku.net/profile.php?mode=viewprofile&u=15048

And I'll say it politely - Stop making ridiculous topics. (If you are indeed a troll read no further)
Get to know the topic trends, post in existing topics. If you start making silly threads right off the bat after joining, no one will take your posts seriously in the future and you aren't making the best of impressions (not that it matters on the net).

EDIT: Raison d'être of the "EDIT" button is to prevent THIS from happening.

Now use the newly learnt method to kill that topic.

OT - Use the EDIT button yet again to request a specific post deletion (yes it multifunctions!)