Hello! I am glad you're reading this. It's people like YOU which can bring this project to another level. So thank you for considering to contribute to this project.
The requirements for a specific task strongly depend on the nature of the task itself. There could also be some tasks which require non-technical skills. But generally, you should have used the Soundcycle loopstation at least once and be a bit familiar with its functionalities.
Technically, you should be familiar with the tools on which Soundcycle is built on: Sountility. It's a collection of libraries for the WebAudio API which are internally used by Soundcycle. Simply put, this project is just an User Interface built on top of those tools. So if you're chasing a bug or wanting to fix/add something which is not (only) related to the UI, you will likely end up playing around with Sountility.
Here's a list of open tasks currently maintained by me: TODOs.md. This list can act as an inspiration for you where to start contributing.
But as I already said it's just an inspiration and my vision for where the project should go. I am sure that you are going to have ideas which are ways better than those!