How do I start using Ruby commands in the terminal?

Hey so I downloaded everything for the environment, but I’m confused on how to get going with actually using Ruby.
I’m following along with the lessons but I want to physically define some methods and play around with the Ruby commands in the terminal. How do I do this? I know i will need to know how to do this when it’s time to start doing some actual problems.
Thanks in advance

Open the terminal and type: irb

Might be helpful:

Ok this works! Thank you!