We know very little about working class Romans because most were illiterate and left no written records behind. We sometimes see them through the eyes of upper class Romans but we should apply a healthy degree of skepticism toward these accounts. If wealthy Romans said the poor were happy with their lot in life, I wouldn't take them litterally. The wealthy always say the poor are happy. Similarly if upper class Romans accused the lower classes of being stupid or foolish, we should consider the prejudices of our sources. Archealogy and other sources contribute some knowlege of the poor, but the picture is still incomplete.
The Roman Empire was large and long lasting. Do you have a particular time and place in mind?