Sarah's Homework:

I'm in a bad mood when things aren't going that I wanted.
Once I had a cool cap, but its gone for good.
I'm wide-eyed when I see something beautiful.

correct:

1.  I'm in a bad mood when things aren't going that I wanted.
~ I'm in a bad mood when things aren't going the way I wanted to be.

2. Once I had a cool cap, but its gone for good. 
~ OR Once I had a cool cap, but now it's gone for good.
Explanation:

Its - Belonging to or relating to something that has already been mentioned.
It's - A short form of it is.

3. I'm wide-eyed when I see something beautiful.
~ CORRECT

Note:

Thank you for submitting your homework Sarah you did a great job. I appreciate your effort, read some of your corrections and keep practicing how to write in a complete sentence to enhance your English Skills.