RE: New to the Sport
You should be still good at 50lbs even with the older bow. Make sure your shooting a good broadhead, I would go with a magnus stinger or something. Next practice practice practice, You'll get stronger in time. Just make sure you are accurate and you'll be good. Make sure you have good arrow flight as well.
OH and PS
When I say accurate, I dont mean the idiots down at the range sayin i can hit a paper plate at 20 yards i'm good. I mean hitting a quarter at 30.