Lots and lots of good options…but lots are near a pub rather than near towns (with the exception of Keswick and Ulverston I think). If you want to paddle something, then somewhere round Derwent Water would be a good choice. Accessible for Keswick, and boat hire from Platty+ is a good option. Borrowdale is also a gorgeous valley, and parts of the Borrowdale bash are very accessible. Also, the cafe in Grange is nice, and if you don’t mind camping outside town then Chapel House farm is beautifully sited.