Docker Desktop includes a standalone Kubernetes server and client, as well as Docker CLI integration. The Kubernetes server runs locally within your Docker instance, is not configurable, and is a single-node cluster.

Refer to : https://docs.docker.com/docker-for-windows/kubernetes/

The Kubernetes server runs within a Docker container on your local system, and is only for local testing. When Kubernetes support is enabled, you can deploy your workloads, in parallel, on Kubernetes, Swarm, and as standalone containers. Enabling or disabling the Kubernetes server does not affect your other workloads.

You can deploy a stack on Kubernetes with docker stack deploy, the docker-compose.yml file, and the name of the stack.

docker stack deploy --compose-file /path/to/docker-compose.yml mystack
docker stack services mystack

To be able running on kubernetes specify the orchestrator in your stack deployment.

docker stack deploy --orchestrator kubernetes --compose-file /path/to/docker-compose.yml mystack

1. Create a volume directory for nexus-data. I used /nexus-data directory which is mount point of the second disk
2. mkdir /nexus-data
3. chown -R 200 /nexus-data

Exaples Apps :

version: '3.3'

services:
  traefik:
    image: traefik:v2.2
    container_name: traefik
    restart: always
    command:
      - "--log.level=DEBUG"
      - "--api.insecure=true"
      - "--providers.docker=true"
      - "--providers.docker.exposedbydefault=true"
      - "--entrypoints.web.address=:80"
      - "--entrypoints.websecure.address=:443"
    ports:
      - 80:80
      - 443:443
    networks:
      - nexus
    volumes:
      - /var/run/docker.sock:/var/run/docker.sock

  nexus:
    container_name: nexus
    image: sonatype/nexus3
    restart: always
    networks:
      - nexus
    volumes:
    - /nexus-data:/nexus-data
    labels:
      - traefik.port=8081
      - traefik.http.routers.nexus.rule=Host(`NEXUS.mydomain.com`)
      - traefik.enable=true
      - traefik.http.routers.nexus.entrypoints=websecure
      - traefik.http.routers.nexus.tls=true
      - traefik.http.routers.nexus.tls.certresolver=myresolver

networks:
  nexus:
    external: true

The easiest way to experiment with Kubernetes locally is with Minikube.

As for a docker registry, I would suggest running the official registry image from Docker Hub. When you want to step up, Nexus is a really nice choice.

1. If you want to play with Kubernetes, the latest version of Docker Desktop allows you to setup a fully functional Kubernetes environment on your desktop, and enable this with a click, see image below and here Docker docs

2. A private registry allows you to store your images, and pull offical images provided by vendors. That's a cloud service, Docker Hub is just one of many repositories available.