QcCowboy

in all truthfulness, there is no "best software" for composing.
you certainly won't learn how to compose from software, only a good teacher can give you that.
software, on the other hand, is a great tool for getting where you need to get with your composing.

1. if you only want the sound files and have no interest what-so-ever in notation, then use a sequencer, there are a number of these programmes on the market, at different price levels and degrees of complexity.

2. if you want to have a notated version of your music (ie: to give to people to perform live) then you're better off going with one of the notation/sequencer programmes like Finale or Sibelius. If I'm not mistaken both have a "low end" version of their product that is less expensive.

3. get used to working with a pencil and staff paper next to you. you can jot down ideas much faster on paper than on a computer. the reason I say this is that the computer tends to act as a trap when you don't have the musical/technical training. It often pushes you to keep things you might normally have rejected had you put them down on paper. I have a whole set-up with 2 computers, 2 screens, 4 printers, 88-key keyboard, a rack of external synths/samplers and internal virtual synths/samplers, and I STILL have a stack of loose staff paper on my work desk next to me when I'm working.

4. I repeat - a teacher. I can't encourage you enough to find a good teacher, someone with whom you will be comfortable. A good teacher is a friend, a mentor, a sounding board. A good teacher will impose things on you, and at the same time encourage you to explore and be yourself.