I would still check your deeds as to whom does own that boundary & ultimately the maintenance, or not, of that fencing.
BTW what aspect is it? Soil type?
If your old border had Conker trees & hedging then the soil is likely to be pretty depleted of nutrients & dry & compacted. It'll be money well spent getting the soil back into some sort of decent shape before you plant anything. Were the tree roots & stumps removed? If not, then that's a job for a young man & pickaxe! Once they're all out then adding as much compost/manure etc will really help.
Sorry to be so negative, but buying new shrubs/plants & seeing them fail is so heartbreaking as well as expensive. However lots of small trees & shrubs take off a lot better than more mature, & more expensive specimens.
Shrubs- Escallonias, evergreen & flowers. Berberis, ditto, plus thorns if so required as a deterent. Viburnums, Hebes. Pyracanthas. Azaleas if soil acidic enough, also Pieris.
Trees- Holly, Hawthorn, Spindles- all good for wildlife. Amelanchier is one I'd always have. Smaller silver birches too- less dense canopy so planting opportunities beneath.J.