This is a good primer on the idea of anarchist communism, I'm pretty sure it can be found for free on sites like theanarchistlibrary.org and libcom.org for anyone who is so inclined. Short and consise chapters makes it easily digestible (it's basically a pamphlet y'all). You can probably read chapter 1-3 in well under an hour which basically answers the what and whys before the author starts getting too bogged down in minutiae (the hows) that might not be as relevant today. The forewords tend to be really dry and focused primarily on situating the text and author historically so feel free to skip it altogether if you're not particularly interested in the history of socialist thought leading up to the 1890s.