Waku needs an Ethereum Sepolia node, either yours or from a third party. Provide a websockets endpoint. You can get one for free from [Infura](https://www.infura.io/).
If you just want to relay traffic in the network, you are all set. If you want to publish messages, you would need an RLN membership. For that you need:
* A wallet with some Sepolia Eth, <0.1Eth.
* Go to [localhost:4000](localhost:4000) and `Register Credentials`. Set a `password`` and `Export` it as `keystore.json`
* In your nwaku node, set:
*`rln-relay-cred-password` to the `password` you chose.