RE: Newbie question
You have the answer to your question. Now some advice. You are new, right? Leave the bow wher it is for now and just learn how to shoot it well. This is easier with the weight turned down. There is nothing more frustrating for a new shooter than trying to learn to shoot when he's struggling with the bow.
You have all summer to work up to a higher weight. As for possible retuning? It should only take a few hours at most.