LingoDeer has more of a focus on slowly building vocabulary and grammar skills. I tend to switch back to it if I find myself stuck on Duolingo, which just throws you in and says 'good luck, kid'.

• 한국 - Korea
• 중국 - Chinese
• 미국 - United States
• 사람 - People/person
• 저는 (something) 입니다 - I am (something)
  • With 는 / 은 use 는 when the noun ends with a vowel, otherwise use 은.
  • Verbs are always at the end in Korean. Be sure to listen/read all the way through to avoid confusion.

This isn't in LingoDeer's first lesson, but 아닙니다 is the opposite of 입니다, and this is the best place to mention it.