First of all, you should check their users' forum. Lots of tutorials and useful stuff there.
Then, you should try to understand how Generative Pretrained Transformers work. This is because they cannot generate relevant text right of the bat, with small prompts.
Give it a larger prompt and ask it to continue. You'll see that the results get better. The more tokens in the prompt, the better will be the generated content (and the higher your costs will be

)
Try to learn more about few-shot learning and fine-tuning. Especially the latter is very very important for decent results.
Also, keep in mind that OPenAI's GPT-3 is not the only player on the market right now. There are other similar models (two of them have more parameters* than the largest model from OAI - Davinci) and each of them has its pros and cons. All of them are expensive to use. Even the open-sourced ones cost a fortune to run and fine-tune (be it on high-end GPUs or TPUs in some cases). The idea here is to find the perfect balance between:
- your needs in terms of content generation
- the ability of a specific model to satisfy your needs
- the costs of using that specific model
There is no one single tutorial which would cover all of the above areas. And all of the above areas are just a few things to keep in mind when working with any kind of GPT model. You have to research a lot before you obtain some decent results.
*PS: don't get fooled by the number of parameters. There are a lot more variables that make a model suited for a specific task. And a fine-tuned smaller model with a data-set containing a specific task could very well outperform a non-fine-tuned but larger model when working on that specific task.