Members can't delete threads. You can request a mod to delete for you through pms, but it is easier to just change the title to "Lock". A mod will lock it and it will eventually sink to the bottom.

You can't delete topics in the forum yet (I know right) but fortunately, you may edit your posts. Scroll down to where it says "Edit Post", click on that, make the changes you need to update your topic, then click "Submit" once you are done.

Okay thank you everyone :)

Mods actually can delete topics, not normal members. ;)