RE: sight pin intervals
Try starting at 20.Bows now are fast enough that a 20 yd. pin will take care of anything out to that distance with little deviation (an inch or lessup or down) which you can correct (you still need to practice judgeing yardages) with your pin placement when shooting.
If no one has told you yet make sure you shoot from very close out to 10 to see which pin you'll need in very close situations. Example: I can still use my20yd. pin at 5 yds but 4,3 and 2 (sounds close but you have to do it) requires the 30 yd. pin.