Thank you for doing your homework, Lilly!

Here are the corrections:

I went to shopping....
>>I went shopping.

I boght cap, and book.
>>I bought a cap and a book.

Cap is 5000won,
>>The cap is 5000won.

Book is 9900won.
>>The book is 9900won.

POINTS TO IMPROVE ON:
1. Spelling
2. Article