The keys have equally increasing and visible lengths from eachother. The longer your fingers are, the farther you can space out your chords, which for this reason, long fingers are called musical gifts. The easiest is scale was C major.
Most piano players play a bunch of notes at the same time but after sound has begun with the first notes (trills), they rapidly play the next ones in order of the fingers left or right, instead of hitting all the keys at the same exact time to make one big sound. (Which is the difficult and admired thing.) If you want to make classical, and you want to make chords that sound good while playing all the keys at the same exact time, to make big chords, in any scale, space out your chord, from my experience it sounded good. Both hands can be next to each other on the piano as long as the fingers are spaced out on the keys, and it will usually sound great, especially if you try the easiest scale. I came to these conclusions from remembering my first time playing piano. It sounded like a dying cow for 10 minutes, but then I spaced out my fingers and played a c chord, notes c,g,e, only a few keys apart from eachother, still sounded like a dying cow, then I spaced my small fingers even further and played one big 10 note chord in the center of the piano... for a moment I sounded okay.
I wasn't exactly Rachmaninoff in his famous thing, but still...