What is the learning curve for using generative AI effectively?

I've never used this tool other than the demos, but I want to buy an account. I'm going to implement ideas for software products that I've been dreaming about for a long time. What should I consider before buying? Maybe there is already some literature or at least block posts on this topic? I heard that it generates great code, but on the condition that the TOR will be several times longer than the generated code.