Yep, yet another way we’re probably not a “true” prince and are never going to be. Which is a pity because Samir is cute, but his behaviour and personality are really doing him no favours. So at this point all my mc would want with him would actually be casual sex.
But we can’t gain power, at least not truly without an education, starting with actually mastering the language.
Modern government, let alone future alien government is an incredibly complicated mess that someone illiterate just cannot run because the piles of paperwork are enormous. And literacy alone is far from enough to comprehend how things actually work.
Right now our kidnappers idea seems to be to use us like the regime’s Katniss. But Katniss was also perpetually kept in the dark and lacked the education to ever see the big picture and fully comprehend what was going on and what’s more she didn’t gain much in the way of power or influence out of it.
The only thing she seems to have gotten out of it in the end is a husband and wealth. Right now my mc is not interested in romancing anybody, particularly since nobody among the ro’s (except maybe Yusra, but she’s the wrong gender and seems to be only attracted to women anyway) is even prepared to treat us like an adult.
As for the wealth, even after less than a day of being imprisoned in it my mc is already getting sick and tired of his gilded cage to the point where he serious preferred the more simple and honest accommodations on the ship.
Well then up the passive aggressive snark to the maximum, particularly with Kaya. Maybe ask if she wants us to accessorize the out-of-place fancy outfits with some platinum handcuffs, maybe a gold-plated ball and chain?
Anyway the fancy, adult, clothes they want our mc to wear are almost comically out of place with their factual status and agency. For what they actually allow us to do an adult romper-suit Halloween costume would be more suitable. 
I mean ordinarily my mc would probably love nice, fancy prince-y outfits, but not when that’s so obviously just for pretend purposes and far, far from his actual status and circumstances and also because he detests the idea of Kaya in particular actually seeing him get excited about something his captors provide.
Okay some male prince-y outfit speculations for Zemian fashion.
possible prince outfits
Probably inspired too much by the Final Fantasy XV aesthetic, but I obviously lack any real humanoid alien examples.
and more towards the casual side of the spectrum:
My mc would ordinarly probably have a huge preference for the fashionable choices, if this speculation hits anything close to the mark. But since that’s what Carina and Kaya would like most too… 
Unless something like my suggestion below gets included, which would override this, giving the mc basic language lessons and info about the planet/culture would go a long way towards making my mc more cooperative.
Well, if you are still open to this it can be done, but it would likely require one his adoptive parents to be in league with the aliens. You could introduce the Zemian language as a cool made up language for (what kid mc thinks) is a cool, secret, way to communicate with his mom/dad. In addition it would also explain why they know so much about Earth and most importantly are so easily able to track the mc’s movements as their minder probably told them of the cabin weekend in a sparsely populated area and how it would be infinitely easier to make us disappear there, versus kidnapping us from our job or something.
And then the “cool secret language” his mom/dad supposedly made up to communicate with their kid (and kid mc thought they had a hand in co-designing) turns out to be an actual alien language. I mean it can be done, particularly if our Earth minder’s cover job is as a linguist, after all we’ve made lots of functional fictional languages, from Tolkien to Klingon. Turns out the one the mc was taught wasn’t so fictional after all.