In what British city did the Hollies first get together?

Answer 1

Manchester.

Allan Clarke (lead singer) and Graham Nash (vocals, guitar) had been friends since childhood in Manchester, and formed the nucleus of the Hollies in the early '60s with bassist Eric Haydock. In early 1963, EMI producer Ron Richards signed the group after seeing them at the famous Cavern Club in Liverpool.

One of the best and most commercially successful pop/rock acts of the British Invasion, when the Hollies began recording in 1963, they relied heavily upon the R&B/early rock &
roll covers that provided the staple diet for countless British bands of the time.

Answer 2

Salford, a Manchester suburb.