I am trying to solve this problem below:

kubectl version
Client Version: version.Info{Major:"1", Minor:"18", GitVersion:"v1.18.6", GitCommit:"dff82dc0de47299ab66c83c626e08b245ab19037", GitTreeState:"clean", BuildDate:"2020-07-15T16:58:53Z", GoVersion:"go1.13.9", Compiler:"gc", Platform:"linux/amd64"}
Unable to connect to the server: dial tcp 192.168.0.10:6443: i/o timeout

And i found answer on some stackoverflow post that i am trying to solve

$kubectl config view 
apiVersion: v1
clusters:
- cluster:
    certificate-authority-data: DATA+OMITTED
    server: https://192.168.0.10:6443
  name: kubernetes
contexts:
- context:
    cluster: kubernetes
    user: kubernetes-admin
  name: kubernetes-admin@kubernetes
current-context: kubernetes-admin@kubernetes
kind: Config
preferences: {}
users:
- name: kubernetes-admin
  user:
    client-certificate-data: REDACTED
    client-key-data: REDACTED

And after that i wrote following command and got this below:

$ kubectl config use-context docker-for-desktop
error: no context exists with the name: "docker-for-desktop"

And after that i'am running sudo docker ps and i get this picture below:

How can I solve the Unable to connect to the server error??

Unable to connect to the server: dial tcp 192.168.0.10:6443: i/o timeout

Above error means Kubernetes API Server which is supposed to listen on port 6443 is not running for issue in kubeadm init process. This can be verified by checking if a kube API Server container is running or not by sudo docker ps | grep api

Disable swap and reboot machine

sudo swapoff -a 
sudo sed -i '/ swap / s/^/#/' /etc/fstab

Uninstall and reinstall kubernetes by running below command

sudo kubeadm reset -f
sudo kubeadm init

As a sidenote if you are trying kubernetes on a local system I suggest to use minikube or kind instead of kubeadm.