It all comes down to personal taste. Some people prefer doing chords first, others drums.
I personally prefer doing the Melody first, then drums, chords, transitions and so on.
To improve the beat, try some minor mixing techniques like panning, delay, reverb. The piano sounds very generic, but that can be improved upon by using modulation like gating, flangers etc. Some transition/rise affects would be a good addition too.
Considering the beat is simple, I could see someone like 2Chainz or Gucci Mane on it if I'm honest, so good work. The only downside is 100k+ other dudes have already made this beat, so learning a bit more about mixing and making your sounds a little more unique is a good start.
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