am so upset,don't know what went wrong where
I went for an open day in Toronto yesterday however I arrived at 920am, at this point the doors was closed
I think you just answered your own question.
As for DOJ, they told me any more than 6 months from the offer they cannot accommodate you, you must reapply from the start. So to be safe I would put at most 3 months in case for any reason things get held up at either end.
Also if they say they take holidays already booked into account- don't bet on it 100%- they will try to give you leave if possible but if things are busy, forget it. I know of several crew who missed holidays they had already paid for. You are starting a new job, your leave does not carry over and Emirates have no obligation to honour things booked before they employed you (my friend had to change the date of her own wedding!!)