From what I can see the board is a twin shape so centre the bindings on it. For width just go with a comfortable natural width. the wider the more stable you will feel. as far as angle that is all personal preference as is the width. if freestyle is more your thing go with trying a duck stance maybe start with a 12 or 15 degree angle front and rear.
it will be a good start and just adjust as you ride it till you find something that suits your riding style.