Firstly, I would suggest not starting anywhere but the beginning. The input section comes first so you should create an Input method first. Just leave everything else until you have the Input method working. Like I said, look at the section and work out what you need to bring into that block. Only once you know that can you hope to write a method declaration.

Now, with the Input section you have two choices. You can either call a method once and have the loop inside it or keep the loop in the event handler and call the same method multiple times inside it. I'm guessing that you're actually supposed to use the second option. In that case you'd need to pass in the StreamReader ByVal and the three array elements ByRef. The reader gets passed by value because you're not changing it and the others by reference because you are.