Be very familiar with what each knob, slider and button on the DJ machine does and how it functions.
The metronome, for example, is very important. You can just play around with it.
There should be an extensive library of dance music. This will allow you to make your own music.
This way, you first listen to a familiar set of songs to start, and then find a song as the opening song, and then the idea to find and find a direct up. After you're done, listen to it and look for flaws. How to gradual how to control the atmosphere how to make the overall harmony, have a theme.
If you're going to make a stand-alone piece, then you're going to need an electric piano and an orchestra.
I can see that you are an audiophile and can afford to buy all this equipment. I love DJing, but I'm just a hobbyist. I'm not even an amateur .......
Seeing more world-class DJs live can be very rewarding.