Allo!

Drumatic/drumazon for the creation of kicks, subs and other 909/808 perc sounds. Good to learn about ADSR envelopes and how they work, and the fundamentals of percussion synthesis.

If you're feeling brave you could start learning Reaktor for synths.
Its a pretty steep learning curve as its essentially a modular programming language, but you'll fully learn the basis of synthesis. Plus the modules and presets it comes with are unreal, and there's millions of them about. Well worth the investment - and you'll understand pretty much every synth VST once you learn reaktor.

There are a million VSTs out there - but I'd stick to those two to get you started. They are flexible, incredibly powerful and will set you up properly

Also
PSP Nitro - for mangling effects and creative distortion
Timeworks Reverb - for a simple and classic reverb

Compression is essential - but you need to learn how it works and what the principles are. You could do worse than start off with the native bundle, which has a simple sidechain/compressor set up + some other good bits and bobs, reverb & some eqs

Best of luck mate