You want to stop being the person who "hasn't got round to AI"
Start with the AI Survival Kit. It is written for someone who has opened ChatGPT twice, felt underwhelmed and closed it. It organises tools by the job you are trying to finish — writing, research, slides, data, code review — and gives a 90-day sequence so you are not choosing between 400 tools on day one. Skip it if you already build with APIs; it will feel basic.