Route from Gretna to Port of Tyne

[Mullerstraße]

Hi folks,

I am setting off on my first major adventure on the bike the weekend - cycling from Glasgow to Berlin.

On the second day of the trip I will be cycling from Gretna Green to the Port of Tyne to catch the ferry to Amsterdam. I was wondering if anyone has cycled this route before and has any tips on the best route to take or places to avoid?

Thanks