Welcome kubamadon,
Well there are many programs that are available as a "trial version" or demo (limited functionalities) to test and see if you like before you invest money.
DJ Chriss (another member of this community) is using a program called BUZZ, which is free, available for download with all the extensions here:
http://www.onlinedj.com/general/portal//search.cgi?query=buzztrack
But be careful, just so you know, BUZZ is not easy to use at all, and has MANY extensions, which are "new instruments" to use inside the program. It is a very cool programand you may love it, but you won't "create a whole music" the forst time you open it.
ALSO, there is one called ReBirth, that's A LOT EASIER and user friendly, available at
http://www.onlinedj.com/general/portal//search.cgi?query=rebirth
Rebirth is not free, but it is really a good program to start making your own music (from the notes to the mixing etc..) insode one program (unlike BUZZ you can use this one right away).
And best of all, a HUGE TUTORIAL of 16 pages will be published here in a few days (sometime this week) which willc over everything you have to know with training exercises
and more will come
So stay tuned, and check those links for today, read other people's posts, you may find some useful hints already.
Take care and good luck