If you get a cheap amp - it won't sound it's best, but if you MUST, at least get an amp made for keys or vocals.(full range requires a horn - no guitar amps or bass amps)
Peavey KB30a - it's small powerful and reasonable.
Everyone, and everything I listen to is my teacher. Every instrument, every voice, every sound in nature ... they are all my private tutor ... 24/7 for free.