The dark photon has a tiny photon component so that it can decay into visible particles like electrons. But since the mixing is tiny, it is a very rare event.

I don't really understand what this means. If a dark photon has no charge and is unlike a photon, how can it have some photon component and release electrons...

I also don't understand what a dark force is.. like what property is a dark force. I understand other forces and what they represent, a dark force is just an interaction between dark particles? What exactly is a dark interaction? It's an attraction caused by what?