Is there any restriction on being able to access a website made available externally either by ingress or nodeport service from a cloud playground K8s cluster ?
You can access them in your browser like this
Enter the node port into the dialog that follows, then it will open the browser
Absolutely you can do it on a cloud playground, so long as the k8s nodes have public IP addresses.
This lab demonstrates it https://github.com/kodekloudhub/certified-kubernetes-administrator-course/tree/master/kubeadm-clusters/aws