My project had serval sensors like humidity, temperature, and EC value. I want to store all the data one column by one column in an Excel sheet. I had followed this tutorial: Auto Logger: log data in daily CSV files (flow) - Node-RED.
Sorry, I don't understand what you mean by that. What is a sheet in this context?
If you use a File Write node to write to the csv file you can tell it to append to the current file so you can add one line at a time.
I am not sure exactly what you mean. Is it that the sensor values are arriving in separate messages and actually what you are asking is how to join messages from different sources into one message so you can add data for all the sensors in one record? If so then see this article in the cookbook for an example of how to join messages into one object.
Import it, look at the help text for the Join node and make sure you understand how the flow works. Then you should be able to use it for what you want.