Congratulations on your new Home and welcome to Permies!
That's a wonderful size of a plot to start your foodforest dream on!
One of permaculture principles is Observe and (then) interact. Take the time to find out how the sun moves on your property through the seasons. What direction does the wind usually blow from? You could maybe tie some ribbons in a tree, bush or pole to have a visual about the wind as you're getting the feel of your place. When it rains, where does the water pool, or wash away quite quickly? That kind of observations will help you heaps as you're planning for future plantings and structures.
I find it useful to have a thick notebook to jot down ideas and experiments in. I'm also keeping an annual list of 'failures' which translate to learning moments.
Yes, I'd wait until spring with getting chicken. In the meantime you can plan where the coop (and the chicken run?) will go.
The direction of the coop and its distance to the main dwelling are worth thinking about. Ideally the entrance door of the coop would be to the east or west, avoiding the wind direction where most rain comes from. (South = summer sun heat, North = cold winter wind). You don't want to have the coop too far from the house (feeding, collecting eggs), but then again, if you're going to have a rooster, you don't want it to be too close either

Make it as fox, rat and marten proof as possible.
I'd plant apple trees and mulberry trees together, and leave the walnut tree in its own 'island'. Then again, there's an apple tree right next to a walnut tree here at our place, planted or sprouted long before we came, and they're both doing quite well.
Start with your climate, soil and elevation. Those will determine what plants might do well at your place. You can also create micro climates to stretch those parameters a bit. Make lists about what you like to eat, what you find pretty, what you know for sure you want and what you might consider in the future.
There's a time for everything; trees do much much better when planted in autumn than if they're planted in the spring (or summer). But will it be this autumn or the next? Probably many autumns to come.
Start with what you know, then expand - the learning never ends!
I made a mistake with fruit trees at my previous place by not paying attention to the height the mature trees would be and bought three dwarf apple trees. Easy picking, but looking a bit funny on the 4000m2.
You'll find tons of helpful information here on Permies, explore the different categories of forums, experiment, engage and have fun!