How many trees?

[Hudson1984]

Wow, what fantastic advice already.
The only thing I would add is why don’t you consider some blackcurrants? A couple of bushes are incredibly easy to look after, yield extremely well and are too tart for the birds to bother stealing / harvesting!
They freeze incredibly well and last at least a couple of years in the freezer if necessary. Perfect mixed with some of your apples in pies or crumbles. Also make fantastic Blackcurrant Vodka!

sounds a good addition definitely.

I think first step will be the apples (and possibly pears to allow for perry or just pollinators for the apples)
then add berries/currants to the shadier areas - or more open areas I have available.

[Northern Brewer]

see what we can sort out. Be nice to get something growing or at least planted this year.

Well the best time of year to be moving trees is when they're dormant, so November/December kind of time which is when bare-root trees are available. You can get trees in pots year-round, but there's less choice of varieties and they can be double the price.

The other crop that's not been mentioned yet is hops....