Your bow weight is 45 lbs at 27.5 inches. To determine what arrows you need you will have to find your draw length.
There are several methods to do this. One of the easiest is to take a full length dowel rod with measurements in inches on the shaft. Then draw back several times and have someone else write down how far you draw back. That will give you your draw length.
Once your draw length is determined it will be much easier to determine what to recommend as a starting point for arrows.