I don't believe there are answer keys.
Without having the code to look at here is what I would do.
- Is there an error message when you play it? Start to read those, note what it says, and you will get better at knowing what they mean.
- What did you just change?
- Is everything spelled right?
- Is it in the right place? Is the syntax correct. I would hover over the toolbox and then click examples to look at the examples.
- Look somewhere different.
This is the fun/frustrating part of CS that everyone experiences.