Whether you use ons or onze depends on the noun. De-nouns get onze, het-nouns get ons
Context. Je eet can be translated to both the present simple and the present continuous.
In English, a verb that is being negated or used in a question (except "to be", but that's another story) needs an auxiliary of some sort. That auxiliary can be a modal or other auxiliary verb ('Can' you help me?/I 'can'not help you.) or an interrogative word ('Who' has the keys?), but if neither of these are necessary, the default auxiliary is "to do" (I 'do' not have the keys.)
While it is more complex than it probably needs to be, that's just how the language works. Dutch doesn't use this setup, so there is no word that translates "do" in this sentence.
What is the difference between ons and onze? For example, it's 'ons bier' but it's 'eet jij onze soep' . Thank you!
Ons is for neuter nouns, onze for masculine/feminine nouns. It's similar to roos/roze, blauw/blauwe and most of other adjectives.
Is this sentence not also possibly also translated as will you eat our soup or are you going to eat our soup?
- eet je onze soep? = are you eating our soup? / do you eat our soup?
- zal je onze soep eten? / ga je onze soep eten = will you eat our soup? / are you going to eat our soup?
"Je eet onze soep?" = Is correct with the right intonation. Normally this sentence is more used like a statement: "You eat our soup."
"Eet je onze soep?" = Is most correct answer. Verb is in front because it is a question :-)