Any good free software to create music as a total amateur?

Have some ideas of samples i'd like to use and try to make some dance music. I can imagine the finished product in my head but have no experience of using music software or such. Years ago I dabbled in djing on vinyl, but that's about all the experience I have. Any Ideas of where to start? Names of programs to try (preferably free downloads until I see if it's worth my while buying better stuff)? Or any other tips?