Hey Champ,
And welcome to the developer community forum, you’re definitely in the right place if you want to learn! (The forum has a great search function btw, you’ll find many solutions to common problems here)
The error message indicates that the model gpt-4 does not exist or you do not have access to it. Please ensure that you have the correct access permissions and that the model name is spelled correctly.
I’ll suggest you follow the advice by, @_j, that’s usually the quickest way of solving this, we’re not able to help you gain access.
You can see which models you have access to over in the playground, under the “model” selection tab in the settings:
https://platform.openai.com/playground
I hope that helps!