More specifically, I am wondering about the English speaking people. I'm curious how different it is from modern English. I realize that this is somewhat of a hard question to answer, but I'm kind of assuming that the texts from the era are not representative of how a working class individual would speak. I can see this being hard to verbalize so if I can be pointed to a video or something of the sort. For example, what would a conversation between a merchant and a buyer sound like? Thanks.
Do you mean the Early Middle Ages (for England pre-Norman Conquest), during which the people would have spoken Old English, or the High and Late Middle Ages, when Middle English was spoken.
This is Old English: Hwaet we gardena in geardagum, þeodcyninga þrym gefrunon, hu ða æþelingas ellen fremedon!
This is Middle English: Whan that Aprill with his shoures soote The droghte of March hath perced to the roote, And bathed every veyne in swich licour Of which vertu engendred is the flour
I'll answer more in-depth for Middle English, because there are more extant sources pertaining to your question. Naturally, there were massive differences between how people spoke, and texts do not necessarily reflect the oral reality of Middle English. However, dialectal differences can be picked up in different texts, which has helped compile the online Linguistic Atlas of Late Mediaeval English for instance. This wonderful database manages to pinpoint how and where what variations were recorded, which helps us understand how the dialects of Middle English interacted. In addition, texts themselves show the (often comical) variations in speech. In Chaucer's Canterbury Tales, the friar in the Summoner's Tale shows an affectation for using French (for which he is mocked), while the students in the Miller's Tale speak in a funny 'northern' accent. Despite their differences, they are still understood though! So, while a text may not be representative of how every working class individual would speak, it gives an approximation of what was considered uncouth or acceptable.
The Riverside Chaucer, ed. Larry Benson Simon Horobin, Chaucer's Language Norman Hinton, "The Language of the Gawain-Poems," Arthurian Interpretations 2 (1987), 83-94