Very Good today Mingi~! You talked a lot today and you shared your vacation story. I am glad you had fun in Korea~ There are just a few corrections in your grammar. You forgot to use the past tense when talking about the past. but that's okay because it's been how many weeks since we studied I'm sure you'll remember them again. Below are the corrections:

You said: Play with my friend and eat a many food.

Correct: I played with my friends and I ate a lot of food.

You said: I'm go Lotte World.

Correct: I went to Lotte World.

You said: I'm eat hamburger.

Correct: I ate a hamburger.

You said: We can't see so many time.

Correct: We haven't seen each other for a long time.