Good Luck Dicegirl.
Just one top tip, allow more time than you'll think you'll need to get to hangar 6. As any lateness is noted, and BA have a points system and if you hit a certain amount of points, they have the right and will terminate your employment.
Also, hangar 6 has a small "restaurant", I use inverted commas' for a reason..you'll soon find out why
and can be a little expensive if you are there every day. So try and bring in sandwiches/salads etc. As for the first few months until your flight pay starts to accrue you will be on a very basic salary