Good on you for getting into making tunes. It’s all uphill from here.
A typical, straight-forward and free subtractive synthesiser is Synth1. What you will learn using it is easily translatable to popular synths like Massive, Sylenth1 and Serum.
I believe Reaper continues to work in its full capacity even after 60 days have elapsed.
You wouldn’t specifically need to find resources about making drum 'n bass in Reaper, just a) learn how to use Reaper, b) learn how to make drum 'n bass and c) put two and two together to get four.
Reaper’s manual plus YouTube videos and the Cockos forum will help you with the former; YouTube and other internet resources will help you with the latter.
Dubstep isn’t obviously easier to make than drum 'n bass. It is probably about the same order of magnitude of difficulty.
If you have some money to spend on a commercially published book, there are some which may helpful, for example ‘The Dance Music Manual.’
I happen to have an extra copy of Williams and Webster ‘Experiencing Music Technology’ and Bartlett and Bartlett ‘Practical Recording Techniques,’ the acquisition of which is a slightly long story. If you’re happy to pay the postage I could send either or both to you to help you get started up.