i don't think so... 1 month is too short.... just forget about korean and enjoying your trip here they already knew the english as simple as you can learn for a month just remember this"고맙습니다_gomapsemnida" for thanks, it'll be enough...

Honestly, I don't think you can make it in a short period of time(2~3 weeks?) I know some foreigners who have been over 10 years in Korea, but their Korean is just halting(No offense to them) except when they say some basic common phrases. Korean language requires you to put everyday effort into studying its constructure - you'll really have to be highly motivated if you decided to learn it.

it's all up to you,if you really want to know more about korea ,i think you may be... but just go for a month it‘s too shorttime to you maybe you can learn simply words what they also uesd,then it will more helpful to you communite have a good journey~~~