As a pianist melody improvisation will probably be your strong suit. So your weak suits will be sound design, and writing drums. Probably focus on sound design first as the drums you’re probably going for aren’t ridiculously complex. Filters, EQ, and compression, learn them. Before you start mixing in electronic sounds, try getting a good recording down of just piano and drums. Then add sub and make sure the mix retains clarity, and then start experimenting with sounds.
Reverse engineering presets is good way to get your feet wet. I like to find presets that have insane amounts of modulation going on and just start turning shit off like crazy, then turning different things on and creating an original sound. Of course you need to KNOW what you’re enabling/disabling for this method to work. Just some advice for down the line.