It is the Children's Day.
REMEMBER: We don't use articles (the, a and an) for name of holiday.

It is on May 5th. ✓
I will wake up early because mom and dad will buy a camera. ✓

We will go to the department store, buy a camera and I will take some pictures.
REMEMBER:
>The pronoun "WE" is used to indicate yourself and other people who will go with you.
> We use "to the" to indicate direction.
> We have to use the expressions 'some and few' to indicate the number of the subject in our sentence.

Hi, Ellie!
Please, review the corrections I gave you. Let's also talk about it in our class later. Thank you!
-Teacher Joanna