G'day Mate.
I reckon I can help you with your dilemma. First of all, lets cut down your tasks to make them seem more manageable.
1. You need to get information from a sensor.
2. You need to send that information online
3. You need to display on a website.
For the first part, you simply must hook up your Sensor(Max6675) to your ESP8266 and code it so as to get the value of temperature.
Your ESP8266 should then be coded to connect to the internet. The microcontroller now has information about the temperature stored within it locally.
For the second part you simply need a database to hold our data, I see you are using node.js so I am assuming you are publishing it to a website. Thus I advise you to use the firebase database, this is an extremely versatile database which I myself have used in many projects for clients before.
Finally, once you have the information in the database you can easily display it onto the website using inbuilt firebase UIs.
Thank you for your time and I hope I have helped you today.
Mohamed