Short answers, pulled from the story.
Ancient Rome had multiple overlapping social hierarchies rather than a single class system. The primary divisions were patricians and plebeians based on ancestry, property-based ranks in the Centuriate Assembly from Equestrians down to the Proletariate, freeborn versus slaves and freedmen, and distinctions between full Roman citizens, Latin allies, and foreign peregrini.
Patricians were the hereditary upper class who controlled the best land, dominated the Senate, and exclusively held the office of the censor. Plebeians were the lower class, mostly laborers and farmers. By the second century BC the practical distinction had largely dissolved, as many plebeian families had grown wealthy while some patrician families had fallen into poverty, though no amount of wealth could move a plebeian family into the patrician ranks.
The Centuriate Assembly assigned voting centuries based on property and military equipment. Equestrians held 18 centuries and Class I citizens held 80, giving those two groups 98 votes combined. All remaining classes together held only 95 votes, meaning the wealthiest Romans could outvote the entire rest of the assembly.
Free-born women in ancient Rome were citizens but could not vote or hold political office. They were under the legal authority of a paterfamilias, either their father, husband, or eldest brother. By the end of the second century AD, marriage sine manu became standard, allowing women to control their own property after their father’s death and permitting either spouse to initiate divorce.
Slaves could be freed through manumission in several ways: as a condition of an owner’s will, by purchasing their own freedom with savings accumulated from business activities, or by direct grant from their master. Once freed, they became liberti, full Roman citizens but ranked as lower-class plebeians. Only their descendants, after several generations, could rise to the equestrian or senatorial ranks.
In 212 AD, the emperor Caracalla, who ruled from 211 AD to 217 AD, issued the Antonine Constitution, granting full Roman citizenship to all free-born men in the empire. Before this, distinctions between full Roman citizens and foreign peregrini had persisted throughout the Republic and into the imperial period.