Long time now since I lived up Northumberland, but coarse fishing around that area is very thin on the ground. Quarry ponds either side of the road just S of Seahouses on the golf course used to be not bad for roach and perch but last I heard you couldn’t fish them any more and also imagine given their location they’ve been well and truly cormoranted.
The big lake, better known as the North Sea, isnt bad in places.
If you want a go with coarse tackle , Craster Harbour a few miles away isnt bad- fish inside the little harbour from the South wall either side of high tide. Used to get loads of coalfish there especially when the kipper factory outfall was running !!) Coquet estuary a few miles south good for flatfish and coalies- fish from either the quayside at Amble or ( a bit quieter) the breakwater on the Warkworth side. Can generally get away with coarse gear as tide doesnt run too hard.
The little harbour at Beadnell itself used to be OK for little flatties and coalies over high tide.
With carp gear, worth a go off the rock ledges at dusk or early morning. Should be mackerel around as well as the usual coalfish. Recommend Cullernose Point just south of Craster and Dunstanburgh Head ( North of,,)Both very snaggy but can get decent coalies, the odd pollack and some wrasse as well in the rock gullies.
Above may well have all changed over the last decade or three

Jolly Fisherman at Craster, and the Ship at Low Newton both highly recommended for an apres-fish, based on a nostalgic visit a couple of years back.

Incidentally one of the rock gullies just north of Beadnell goes by the splendid name of “Nackers Hole”, with “Lady’s Hole” nearby. Make of that what you will….