I am a total beginner with some questions

I really like programming (I've done some in C) and I decided I wanted to try doing some programming on my Mac. I spent hours online trying to find something that I could learn and settled on Squeak. I have it and barely understand the basics of it.

A few Questions:

1. What do I do to test whether or not a key has been pressed (in a method I want it to say 'if C key is pressed down do this')

2. What do I do to display a picture that I have on my computer?