I knew kawaii before i was learning japanese.When i actually started learning the language i think the first word i learned was genki, It was a long long time ago so i cant remember if its true.
I have no idea I think it was maybe like Sayonara. One of my first grade teacher's husband was Japanese so it'd be a bit harder for me to be completely sure about the "first" word. That would've been like in 92 or 93.
chikara - it means power,capability. I liked it so much i ended up using it as my online name in a lot of places. I also have the kanji for it tattooed on my shoulder blade