Streamer,
As a cadet, until you have 1500 hours, you will start around £24000 and that rises in increments on hours achievement to around £32000. You will be a Second Officer.
Only when you have 1500 hours will you be promoted to First Officer. These scales kick off at about £36000. They rise to well over £50000 after an awful lot of years if you are never going to be in command.
All rough figures, but should help.