Again, well done on getting an apprenticeship!
I'd start with the bare essentials:
stanley knife, hammer, pliers and sidecutters with slipguards (Stanley are fine),
screwdrivers (CK are fine).
Then as mentioned build up the tools you need but haven't got - hacksaw, combination square, bell set, pipe cutter, waterpump pliers, adjustable spanner, allen keys, battery drill etc.
Brands such as Stanley and CK might not be as good as something like Knipex, but they're good for the price, which is a factor to consider if you're new to the game and if you haven't got much cash to spare.
It's worth only taking on site tools which you can afford to replace - nice tools have a habit of growing legs.