I need help using Twitter, please help me...?

[Emm]

There should be a blue box with a quill sign on it, that is what you press to write your own tweet.
To reply to someone else's tweet, hover your mouse ove the tweet and at the bottom a few signs will come up. hover over THEM and click the one that says a reply and start typing.
To see if someone has replied to any of your tweets, click the @ sign that is at the top somewhere. This also shows you if anyone has followed, retweeted or mentioned you in their own tweet.
And finally, a 'trending topic' is something that a large number of people are tweeting about. If you have set your location to, let's say, the uk, then the trending topics will be those that a lot of people in the uk are talking about. For example, sometimes when a good movie is showing, naturally a lot of people will be tweeting about it and letting their followers know. If a large number of people then start tweeting about the film, it will become a trending topic.