where can I find a book that explains Marxism *URGENT*Watch
I do not think however that Marxism has an ideal society. It is not meant to be a prescriptive or normative theory. Marxists will not or should not give recipes for what a future society will look like, let alone an ''ideal one''.
If you meant, what is the last stage of human development according to Marxists, then that is ofc communism. A society where private property in the means of production does not exist, that is, productive property is commonly owned by all. People can have possessions ofc but there'd be no need for any individual to own productive capital. Abundance of goods and services will ensure that all will receive as much as they want of literally anything the society produces (no scarcity). People will not specialise in any specific task, like say being a dentist, they'll be able to survive without working and do whatever their passions drive them to do.
That is a summary of what a communist society will look like. But it's important to say that there's no ideal society for Marxists because Marxism is a positive theory, a descriptive theory of how societies evolve and change, it's not a moral theory of what ought to be done to achieve some ideal society. It's inevitable that if people want to do away with the alleged contradictions of capitalism (briefly: wages can be high only if profits are low but if profits are low, there's no incentive to invest and therefore no economic growth. If profits however are high, wages must be low in which case there'd be no demand for the products produced. Businesses go bankrupt, unemployment is increased, etc. The only way to do away with this, Marxists say, is to have a system where property is commonly owned, there's no private profit and private investment, etc) they must revolt and change the way production is organised. The details, that is, how would such a system function was classically considered unanswerable or something for the future revolutionaries to discover.