Look in the node red cookbook for examples on using http. But, as I said, using that method would require opening ports on your router, so you would also have to look at this FAQ post for advice on how to safely access node-red over the internet.
What don't you understand about using the email node.
As a beginner, I recommend watching this playlist: Node-RED Essentials. The videos are done by the developers of node-red. They're nice & short and to the point. You will understand a whole lot more in about 1 hour. A small investment for a lot of gain.
