You can run a one-node etcd cluster for testing, but it's not recommended for any real usage.
Most companies won't be running their own etcd clusters anyway, except for on-prem clusters. Cloud users will generally use a managed Kubernetes cluster. If you do need to learn how to run etcd, you can learn the basics in about a day. In our org, the etcd portion of the training is less than half an hour long thanks to good documentation.
For a homelab, consider running something like k3s which can use a SQL database instead of etcd.
Kubernetes depends on etcd which requires an odd numbers of instances. There might be ways to run a one or two nodes cluster for testing (see minikube) but that's not how it's going to run in a company.