Brand spanking new bottom bracket and crankset – but there is this clicking noise when you pedal! Any ideas what might be causing it?

Can’t tell.

Look at everything that’s moving. What bit is in the same position each click? Where is the sound from? Can you feel the vibration anywhere?

Since the BB is new, I’d focus there. Drop the chain and spin the cranks, so you can can remove some variables and maybe isolate the noise.