Good advice...
I have problems that require me to shoot light, usually 28#, but didn't have too much trouble working up to a temporary 42# in a month for a recent hunt. I felt I could get away with it because in a hunting situation, you release few arrows (I hope!) On a four day hunt, I released 2. Now I'll go back. By and large, I like, and recommend, shooting light.. not shooting hunting weight all the time unless you hunt all the time. Over a lifetime of shooting, elbows, shoulders and back have to absorb a lot of wear. Shoot lighter, shoot longer is my motto. (I'm 71)
As to arrow length, if you're just starting out, you still have the whole issue of arrow type, wood/aluminum/carbon, and arrow matching ahead of you. Don't worry too much about length. You'll find that length is one of the major ways to adjust arrow match, especially with carbons. (Carbon arrows do not have spine... They only have attitude!) Many folks start with a full length arrow and simply cut back until they get good flight. That's their length, whether it's one inch or four inches past the shelf. Generally, you do want at least 1", so you don't accidentally draw a broadhead up onto your finger. Yours is not the blood trail you want to follow!
Above all, have fun!