Oh I remember you from r/communism before you were banned Lol. I think you also have some type of fetish with hating communists judging by your post/comment history. OK but in all seriousness.
The subjects you’re asking about are kind of loaded. In the sense that there’s a lot of nuance and history to cover. Can’t really just give a couple sentence summary that encapsulates all the ideas and then you be on your way.
When people talk about the millions or kajillions of deaths under communism, we’re not convinced these claims are based in a disciplined and honest analysis of history. These numbers come from the Black Book of Communism as one example. This AskHistorians thread explains why that book is just stupid.
That and sources like Robert Conquest are infamous “historians” whose entire purpose was to create anti-communist rhetoric for capitalist class. Conquest is an entirely different beast so I’ll skip him for now.
These claims of 100 million for example are simply disingenuous and ahistorical. Tragedies under socialism happened certainly, but to separate them from their historical and material context and pretend like they existed inside a vacuum is lacking any sense of nuance or class analysis.
It also helps to be mindful that the entire educational and media systems you’ve been exposed to are actually capitalist-run and have been refined to serve the interests of the capitalist class. For over the past century, anti-communism has been propagated more like a religious orthodoxy than a political analysis as the capitalist class has an intrinsic class interest in targeting movements that threaten their profits and positions of power/privilege.
Simply put, Communists literally threaten to overthrow capitalists and raise the common man up. Why would the capitalists sit back and let this movement spread? They were not quick to realize what the communist movement represented.
Michael Parenti has lectures on YouTube I feel assist newcomers to the Left (covering the history of imperialism and communism for instance). Granted they’re long but they’re written so everyone can understand easily without diving into Marxist jargon and theory. May be worth a spin if you have the time.