Need help in debunking someone's claims

Hi Comrades I'm an aspiring ML (still in the process of studying and acquiring knowleddge, so not sure I can call myself that). As i'm still learning I find it somewhat hard to find proper sources to debunking some claims about the USSR. I am first starting my journey with deepening my understanding of Marxism-Lenninism before I deepdive into the USSR. I know some basic things, but was wondering if someone could help me with debunking the claims of someone that is a USSR hater.

It's a young kid that just finished his IB education so as u may already guess, he's been heavily propagandised. If someone could help me on finding sources or help me debunk this (and also addtionally give sources) I would be very thankful as it'd be a great learning experience for me as well.