Order to teach looping constructs in a non ideal language
I prefer to teach while loops as part of my unit on if/else statements since the syntax and thought process are virtually identical.

I then introduce for loops when teaching lists (in Python) or arrays (in Java).  With for loops, language impacts which style you likely use first.  With Python, I use the for item in list structure first.  In Java, I use the C style (for i=0; i&lt;...) loop first.  

I don't try to introduce all styles of looping at once as I prefer to develop the concepts across units.