Aberdeen is awful for shopping now, Charlie. John Lewis, Fraser’s, Debenhams etc have all gone. It’s very sad. There’s still plenty to see but it’s not a shopping paradise anymore.
I don’t think anyone has mentioned anywhere north of Inverness. Caithness & Sutherland are wonderful counties, unlike the rest of Scotland, with a Scandi flavour to them. Likewise Orkney. The North 500 road is beautiful, although oversubscribed in summer.
As others say, it’s not possible to do Scotland in one trip, so pick your region and then come back again!