i start my 1st driving job on monday, at my interview i was shown around some of the trucks the company use, for the tachos there was 3 symbol positions, the “X”, “other work” and “rest” well i assume thats what they mean
when driving i assume i put it to the “X”?
but what about when im unloading the lorry, do i move it to “other work”
last thing i want is to get in trouble on my 1st day 
The crossed hammers ‘X’ is other work, the square is for POA and the bed is for breaks and rest… Regardless of which symbol it is on it will automatically record driving when the vehicle moves. It is best to keep it on the crossed hammers, which is what you use when loading and unloading, and move it to the bed symbol when you take your break. Sounds like you don’t have much experience of the tacho rules so I would suggest getting to grips with them before worrying about things like POA.
These are the symbols you’re referring to, you should use them as Coffeeholic said.
Other work
Break / Rest
POA
Good luck with with the job.