It really depends what you are looking for on your trip. I recommend the west coast and its islands e.g. Islay, Jura, Mull etc. The scenery is great with some incredible beaches, just not the weather. Islay is famous for its whisky if that's something you are into. West coast is famous for seafood, particularly shellfish. Loch Lomond is worth visiting. The Trossachs region is scenic. If you like hill walks etc it is a good place. I'd probably spend most of my trip on that side of the country. Lots of lochs too if you like tha e.g Katrine Lochgoilhead.
I don't know the north / east coast as well but if you were to go further north the 'North Coast 500' is a well known tourist route that is meant to be really good, you could join part of it.
Unless you really want to see Aberdeen I'd suggest skipping that section and coming down past Aviemore to Perth then along to St. Andrews. Aviemore, Pitlochry, Aberfeldy and Dunkeld are nice scenic places. Perthshire in general is really nice. I'd definitely recommend the Aviemore and the Cairngorm area, especially as your route is so close to it.
St. Andrews is great, lots of good bars and restaurants. I know a few people who regularly visit the villages further round that coast (Elie, Crail, Anstruther).It might be worth going round that coast after St. Andrews on your way to Edinburgh.
Stirlingshire which is between Edinburgh and Glasgow is nice. Stirling Castle/Wallace Monument are worth visiting if you are interested in history. The Devil's Pulpit is famous and was in the show Outlander. Gleneagles is a bit further north and has a famous hotel. If you like golf Gleneagles and St. Andrews are worth seeing.
Glasgow - I'd head to the west end. There are great bars, cafes and restaurants. Good nightlife in Glasgow generally depending on what you like.
@Scottish I'm sure will be able to help.