Chamchi (tuna) kimbap makes for a decent ghetto meal if you're running low on cash. Ja jang myeon is also an inexpensive but delicious noodle dish.
Visit seoul and busan while you're there. The latter gets packed once it starts warming up, it's really a sight to behold if you don't have popular beaches wherever you're from. If you want to network with expats working in Korea, I recommend looking up the local Toastmaster's Club.