I wanted to start planning now for fall planting of over winter crops. I
really have no idea what to plant. Garlic? Potatoes?, Onions?

Garlic will overwinter.

I doubt garlic is the only one, but my personal experience is more
with perennials (e.g. rhubarb, rosemary, mint, oregano, sage, apple,
blueberry, strawberry, etc), than with fall planting of crops to dig
up next summer. Fall planting works well with most perennials
(although I would aim for early fall, as soon as the summer heat has
abated, because the point is to get some growth before it gets cold
and days get short).