I forgot to include this in the post for the last lesson. We did a gift exchange for Christmas and so apart from wishing each other a Merry Christmas, we also did a New Year greeting. (The next time we will see each other is in the new year.)
"Merry Christmas" is... Merry Christmas: 메리 크리스마스.
To wish someone the best for the new year: 새해 복 많이 받으세요!
Bonus (German, since my teacher made me say this the day before for my German lesson): (Ich wunsche dir) einen guten Rutsch ins 2020!
Literally, you are wishing the person a good slide into the new year, kind of like wishing that the new year will be smooth sailing.
It's past midnight where I am now, so it is the new year. Happy 2020!
For myself, I hope it will be a good year, better than 2019... no, not just hope, but I'll make it better.