Well, you can adopt some existing code. (not a bad idea). However, a lot of examples have all kinds of fancy async code, event code. There is HUGE and MASSIVE reason for 50+ years, that hello world programs still exist!!!
They allow people starting out to learn.
So, I suggest you drop in a text box, a button, and then a LARGER multi-line text box.
Say like this form

So, we can enter a command prompt. When we hit run command, it will run that command, and capture the out put.
Code behind that button is this:
Private Sub cmdMyShell_Click(sender As Object, e As EventArgs) Handles cmdMyShell.Click
Dim MyProcess As New Process
MyProcess.StartInfo.FileName = "cmd.exe"
MyProcess.StartInfo.Arguments = " /C" & TextBox1.Text
MyProcess.StartInfo.UseShellExecute = False
MyProcess.StartInfo.RedirectStandardOutput = True
MyProcess.Start()
' get the output
Dim strMyBuffer As String = ""
strMyBuffer = MyProcess.StandardOutput.ReadToEnd
MyProcess.WaitForExit()
' now display this output in the text box:
TextBox2.Text = strMyBuffer
End Sub
Ok, so when I run above, get this:

Or, how about say ipconfig.

So, the above is a really simple bit of code. And if you make the text box large enough (and anchor to the right + bottom), then you can re-size the window.
eg this:

I also used a fixed font size for the text box (Courier new 12).
So above is rather bare bones. If you actually really looking to expand on this? Then I think the other links and sample code are better examples.
I am tempted to post a shell() command with the "pipe" > redirection of output to a text file. but, then that would require you to read a created text file for each commands output from a text file.