Did you check the status of docker and kubelet services.? if not, please run below commands and verify that services are up and running.

  systemctl status docker kubelet

I encourage you to look for official kubernetes documentation. Remember that your kubemaster should have at least fallowing resources: 2CPUs or more, 2GB or more of RAM.

1. Firstly install docker and kubeadm (as a root user) on each machine.

2. Initialize kubeadm (on master):

kubeadm init <args>

For example for Calico to work correctly, you need to pass --pod-network-cidr=192.168.0.0/16 to kubeadm init:

kubeadm init --pod-network-cidr=192.168.0.0/16

3. Install a pod network add-on (depends on what you would like to use). You can install a pod network add-on with the following command:

kubectl apply -f <add-on.yaml>

e.g. for Calico:

kubectl apply -f https://docs.projectcalico.org/v3.8/manifests/calico.yaml

4. To start using your cluster, you need to run on master the following as a regular user:

mkdir -p $HOME/.kube
sudo cp -i /etc/kubernetes/admin.conf $HOME/.kube/config
sudo chown $(id -u):$(id -g) $HOME/.kube/config

5. You can now join any number of machines by running the following on each node as root:

kubeadm join <master-ip>:<master-port> --token <token> --discovery-token-ca-cert-hash sha256:<hash>

By default, tokens expire after 24 hours. If you are joining a node to the cluster after the current token has expired, you can create a new token by running the following command on the control-plane node:

kubeadm token create

Please, let me know if it works for you.