How to Prove Self-Employment in BC Canada?

I'm asking this to help figure out if I'm eligible for CERB, so any help would be tremendously appreciated: 

I have worked as a tutor for a while and made over 5000. I get paid either through e-transfer or cash. I think this makes me eligible for CERB. What I'm confused about is how I can prove I made this money. Does anyone know? I have the e-transfer statement things, but how do I prove that they were for tutoring and not for, say, people paying me back for dinner? And what about the cash? Also, if I provide an e-transfer proof, is there a risk that my client gets bothered by the tax people? Like, would the tax people try to contact the person that sent me the e-transfer? Some of my clients have returned to their home countries, so I don't even know how they would reach them.  

Thanks in advance for any clarifications. I know this is super last minute!