Is the tennis racquet I have good enough?

My mom's friend gave me her old racquet (a Prince Graphite Pro Oversize) and I don't know whether to buy a different one, or if this one is fine... I had an older one from Athletech or something... It was a bit small though. I also don't understand, what does oversize mean? Is it good to have an oversized racquet? And would it be too heavy for me? (I'm a 16 year old girl entering tennis camp and I really want to get on the tennis team, which is very picky). Thank you :)