Hey ! I have used Reaper for several years and I still recommend it. Though, you'll necessarily need VST (so additionnal plugins to download) to produce interesting music. I'm only using free VST and it's enough. I heavily recommend Labs by Spitfire, with which you can download several high quality instruments. Also, I suggest downloading Vital, a free synth that is one of the most comprehensible due to its interface. For chiptune, I also recommend magica 8bit plug by ymck. Finally, for sound effects, I suggest the MFreeFXBundle by Melda Productions. The interface is a little more understandable than the one of Reaper's built-in effects.
BUT !!! If you've never used a DAW, and you don't use a separate sound card for real instruments, some people around me use Bandlab, which is also free and relatively easy to use. It's only online though. It already has everything built in, but you can't add any VST.