Before you proceed, please check our FAQ page for answers to your question.
You should use the existing topics by creating your own page within.
use “Search”, eg. user:comments:my_one, then you get a “Create this page” button and can proceed.
If you think it is helpful to the others you can create own topics.
use “Search”, eg. user:my_topic:test, then you get a “Create this page” button, then just do “Save” to the blank page, that should create the new topic and you can proceed with the first item.
There is also a remarks page where you can just post your ones by editing the page, use headlines to separate.