That's a really interesting place to introduce Kanji for names, Duolingo.
We've actually already met Tanaka way back ;)
So it was her who we have been playing with. :o
What does 「に」 do in this context?
'To'. It's the dative operator
Can i drop the "san" in Tanaka-san?
Yes, but it will sound rude
No. While it is grammatical, you'll only want to use no honorifics with family members and very close friends.