Do you know how to load up 3rd party VSTs and layering samples to one group (the latter is beneficial when using a ton of one-shot .wav files)? Image-Line also has some really great YouTube tutorials on the basics like that.
Alchemy Player - I couldn't find a reliable download, so I uploaded mine into mediafire - CamelAudio is no more, sadly.
As for other FREE and Pay-To-Use stuff, try out KVR https://www.kvraudio.com/
Plugin Boutique is a nice one too http://www.pluginboutique.com/
Native Instruments https://www.native-instruments.com/en/
IK Multimedia http://www.ikmultimedia.com/
Also, hunt down ProtoPlasmTSM and AnviliaFree - they're pretty decent Pad synths that are free.
1. I have access to everything that comes with the Producer Edition of FL Studio (you can find a complete list here), but I mostly use the Sytrus synth. Plus, I have bLiNd's sample drum pack.
2. I'm playing with some of the volume sliders/dials on the mixer and channel rack, and I've been experimenting a little with automation.
3. I'm taking piano lessons, but I have not studied music theory. I also have a Casio WK-240 digital keyboard that supports midi.