In a hypothetical scenario, how would envision how interactions between a human society (don’t have any particular technology level in mind, but anything in the early stages of gunpowder or before that) and any sort of non human sentient species would look like?
As far as what an alien species would look like, well use your imagination. They could have humanoid traits, or be some weird tentacle thing that communicates with a light bar. Since we don't really know how life would evolve on another planet, anything is possible, so have fun with it.
I mean, are we talking Star Trek forehead appliance aliens who are just tricked out human stand-ins, or are we talking something genuinely unlike us? And if it's the latter, then in what ways are they unlike us? Physically Psychologically Socioculturally Religiously Humans only have to be a wee bit different from other humans before we start deploying some very different ways of engagement, and the greater the difference, the less flattering the engagement.
I'd say a lot of it depends on how different their cognitive processes differ to ours. How do they perceive us? As another sentient life form, or as part of the environment. Or perhaps they can't perceive us at all. "It's life Jim, but not as we know it." "Phasers on kill."
Need. More. Input. What's the scenario? Are the aliens invading Earth? Hanging out in saucers over our major cities observing us? Probing ignorant farmers and hillbillies? Landing in the woods and keeping to themselves? Have they made an effort to communicate peacable-like with us?
I’m imagining that these non human sapients are species that coexist with humans on whatever earth like planet they are on. Roughly, they are at best, about the same technology level as humans. If slightly more primitive.
Xenophobes that we are, I doubt that there'd be a good outcome if the white race's encounter with non-whites is any indication.
Stars in My Pocket Like Grains of Sand by Delany includes a setting where humans and another species called Xlv that are vaguely reptiloid and decidedly not of the human bipedal body plan create families that include both species in ever-shifting sexual permutations. There are "runs" specifically for engaging in casual sex within massive lava tubes. Delany spares no detail in the interspecies kink, but the Xlv are amenable, not disturbed in this case.
I quote Londo Mollari, speaking about the extinction of the other sentient race on Centauri Prime: "Do you know what the last Xon said just before he died? "Aaaaauggghh!!!""
I really, really, really depends on several important factors. How similar are they, physically? Note that the other species being non-humanoid with a few human traits could theoretically have a more positive effect that the other way around. (See: The Uncanny Valley.) How... charismatic do they find each other? We would probably have a more positive and forgiving attitude towards a species that resembles adorable teddy bears, for example, than say one that looks like giant spiders. Do they speak the same language? If not, how serious is the language barrier? The ability to communicate clearly is very important. On that note, how similar are their cultures, worldviews, politics and values? A potential issue with contacting alien life forms is that there is no guarantee they think, feel and reason anywhere near the same way we do, which would make it extremely difficult to understand one another even if we somehow figured out the language thing. In extreme cases, we may not even be able to recognize a species as intelligent because they are simply too different from us. How much history do they have with each other, and is that good or bad history? How likely are they to fight over resources, territory, etc? How likely are they to trade with each other instead? How balanced is the power dynamic between the two? I don't believe humans are necessarily greedy, selfish bastards but historically whichever was the "stronger" group has had an unfortunate tendency to abuse and dominate the weaker ones out of self-interest. This should be less likely if both groups are on at least roughly equal standing in terms of technological, military and economic advancement. So, yeah. It depends.
They may come from a planet where survival of the fittest is the norm so if you got it and I want it I’ll take it. Also, the size would relate to available resources and gravity (I believe), so maybe they’re already here COVID -19