You’re supposed to.
I was thinking about writing an e-book. Then I think, "nah, there are already books like “bittorrent for dummies”. Then I see questions like yours and think, “I need to write an E-book”. If I could find an illustrator for it I probably would.
Torrenting is a two-part process. You’re doing the first part. Now you need to do the second.
The first part is getting the .torrent file. This contains, oh, think of it as instructions, for getting “the macguffin”, which is the movie you want to watch / music or audiobook you want to listen to / software you want to install / e-book you want to read / whatever. A .torrent file is human-readable, and you can look at it in Notepad or a simple text editor (don’t try to change it!) it’s just not terribly interesting.
The second part is to open that .torrent file with a bittorrent client like BitComet. The client will then begin transferring the macguffin. This transfer is two-way from the beginning and you cannot prevent that. Bittorrent clients constantly download AND upload. The contents are cut into equally-sized pieces, a great many of them, and these pieces get transferred in blocks.
Unlike most other transfers, torrent transfers are NOT sequential – you don’t get piece 1, then piece 2, then piece 3 and so on, in neat sequential order. Unlike most other transfers, the pieces you do get do not come from a single server – they come from other people just like you, with computers and connections just like yours, all over the world.
Unlike most other transfers, your client is uploading (to others) every piece it downloads. Get a piece, share a piece, share that piece several times with several different peers. All peers choose whom they will connect to, and whom they will transfer with. To download, you must upload, and try to make yourself a good upload partner in order to attract the best download partners.
As an experiment, you can try not uploading anything, by setting the global maximum upload speed in your client’s parameters to 1 or zero (be careful, in some clients, 0 means unlimited, which you do not want to do at all, and isn’t the goal of this experiment in any case). If you do this, then your download speed will drop, drop, eventually reach 0 and stay there. As time goes on and other peers contact you, you slip to the very bottom of their lists, a most UNdesirable trade partner. Soon they will all have done this and nobody will give you anything either. You MUST give in order to get, and bittorrent itself enforces that. (Now reset your upload speed to 80% of your tested upstream bandwidth and restart your client.)
The .torrent file that you downloaded is a few kilobytes in size, and probably happened in mere seconds. The macguffin that you want is much larger - megabytes or gigabytes in size. Obviously, transferring that is going to take much, much longer. Just how much longer depends on your download speed. Your download speed depends on many factors, MOST of which are not under your control.
Since your connection is probably asymmetrical (faster down than up) you will need to continue to seed after completing your download. (You don’t need to do a thing, your client will automatically start seeding as soon as a download completes.) You will need to keep seeding the torrent until you have given at least as much as you took, and reach an upload to download ratio of 1:1 (or 1.0 expressed as a decimal), or better.
Be careful not to run too many tasks at once, most connections won’t support more than one downloading and one seeding task. Make sure your tasks are running at a minimum of 8 KB/s uploaded.