This is a very board question. I'll try to help where I can.
First of all you need a DAW (Digital Audio Workstation). Basically, it is a consolidated array of tools for music production. It functions as sequencer, editor, plugin host (instruments, samplers, synths, effects), recorder, and more.
You have many options, like Ableton Live, Logic Pro, and Steinberg Cubase. In my experience, those three are the most used DAWs for electronic dance music production. Get the demos, take some tutorials, and decide through experience which one suits you better. Some people like to use Ableton Live to play live, compose, and design, and Logic Pro for mixing and mastering, to give one example.
The three are great DAWs, you can't go wrong with those. Perhaps the most popular is Ableton Live, which translates to more tutorials and guides for it, which can be of great help for a beginner. With that in mind, maybe Ableton Live is a good starting point, but test the three anyway to see if you like another one more.
Now that you have the DAW of your choice, learn it. Learn to use audio tracks, MIDI tracks, the piano roll, sends, inserts, etc. There are countless resources out there, so this is not a problem at all.
Instead of knowing where to download patches from, you want to learn how to patch, so in parallel with learning a DAW you want to learn sound synthesis. Here you'll learn about synthesizers, samplers, synthesis methods, effects, parameters, and so on.
Again, the internet is flooded with resources for this. One of the most popular is SoS Synth Secrets. It's a great synthesis course that anyone can take, even absolute beginners (make sure to go through it incrementally, starting from part 1).
Now that you know your DAW and some synthesis you can incorporate the Yamaha synth (and other hardware instruments) to your workflow. Maybe you want to control it through the DAWs MIDI tracks and record it in an audio track. Once you know the basics, incorporating external hardware elements in many different ways is trivial.
You don't need to go into crazy depths to have fun though. With a day or two of knowledge you can start producing, because the basics are really simple and intuitive. You can get an idea of what's going on by following a 20 min tutorial, like this one:
Let me know if this answers your question or if you have any doubts.