Welcome, Jason. That will be a really pretty spot you've got.
For every "massive pond that was well thought out" that you see on the forum, I'll bet there are 10 that are closer to what you've got...and some of the best, most unique ponds here are the size of yours, or even smaller.
At this point, you appear to have already successfully passed one of the first hurdles-your pond is holding water. Congratulations!
So to my mind, there are two really important questions to answer right now:
1] Will you need aeration of some type, regardless of your choice of fish types, to prevent winterkill.
------I don't have enough experience with northern ponds to answer this, but I'm sure someone else will.
2] What are your goals for this pond?
------That will help us help you with what to add and when.
