What to buy for a "semi-professional" first camera?

Hey,

I've been shooting a lot with cheap Cybershots and getting insanely good results. A lot of friends of mine collaborate in Marseille with big artists, and I'm willing to go back into photography with a proper DSLR camera.

I do not mind buying used. Also, my budget is around ~500 euros maximum. I need a good speed (for bursts), and a good image quality in dark environments, since I'm willing to shoot a lot at shows like my friends do.

Also, I live in France.

Right now, I've been looking into EOS 2000D (but turned back cus slow focus & slow bursts)/Sony A6000, since I'm already pretty aware to photography jargon, I am scared to be limited.