ok, so to correct. it is ok to have a round needle....
The thing to be sure of is that the long groove of the needle is facing away from the hook. In other words...
...if your needle sits to the right of the hook (can check by lowering it with no thread) then the long groove goes to the right, and you thread it from the right to the left.
...if your needle sits to the Left of the hook then the long groove goes to the left , and you thread it from the left to the right.
A machine makes a stitch by the thread being pinched by the fabric as it goes through and when the needle is drawn up, the portion between the needle and the fabric does not move, thereby making a loop that the hook goes through.