I think you are right to concentrate this year on getting the house sorted and just seeing what you have with the land. Better to see it in all seasons before you launch in.
'Good fencing makes good neighbours' is a saying worth bearing in mind - it works both ways, keeping their animals off your land and yours off theirs and in your case keeping your children safe too. Our first job when we moved to our smallholding 16 years ago was to get up good mesh fencing around the whole place. We hate barbed wire so took off any which was present and replaced the top wires with plain (all barbed wire does is tear any animals or humans to shreds but doesn't stop either from getting across). Then when Foot and Mouth came along we decided we needed some biosecurity too (to stop neighbouring animals touching noses with ours), so we double fenced the place, with hedgerow in between the two fences. Animals and humans seem to be kept in by that system, but it is expensive, and worth learning how to do it yourself. We have never regretted the outlay on fencing. We still have one length of hedge to plant, as we have done that stretch by stretch when we have had time and cash.
For your possible fruit tress, just observe this year to see what they are, then you can launch in with pruning and so on next year when you can see what's there.
For the veggie garden, again I would wait and see as siting it in a shady place will be a disadvantage. You will also know by then if you want to site it close to the house, and where the best soil is. You might have a problem with rabbits, deer, or pigeons and that will influence your site choice too. Meantime, as someone has suggested, you could start off some plants in containers.
I'm looking forward to following your progress with this - I love seeing how others do things on their smallholdings.