I started making music with nothing but freeware in 2000.
The easiest way to get fun and cool synth sounds is to use a program called Savihost and download some of the hundreds of free VST synths available. I have a midi keyboard, but it's not required. You can use your computer keyboard or simply use the mouse on the graphical keys. Savihost has a built in wav recorder, so all you have to do is use the record button while you're playing and stop when you're done and save.
Link to Savihost(Here's a
good source for free VST plugins, but there are many more.)
To put the wavs together I usually use Acid 3 by Sony, but they used to have a freeware version... Yep, still there.
It's called Acid Express. It's limited by the number of sounds you can use at once, either four or eight, I can't remember which. You can put the wavs you saved in the Savihost program in here and mix them together. Here's the
link to Acid Express 5. (At the top of the page.) There might be a limit on the length of the tune you can make, and if there is, let me know and I'll find a different freeware program you can use. (I've used bunches of them over the years.)
If you want to compose a track with actual midi notes composed like sheet music, try
Finale Notepad. I used Finale Printmusic to create
"Mitsumushi". I'm not sure if you can save as a wav in Notepad, but you can always get
Audacity and record what you created.
I can show you dozens more programs. When I started I had no money for music software and it was too much of a gamble to buy much so I found every free thing I could to make music with. These are my favorites.