As-salaamu'alaikum sister
I am very happy to hear that you want to revert to Islam, I was once a Roman Catholic too and a really strong believing one untill I discovered and looked into Islam. At first I tried denying Islam and staying to my Catholic ways but it wasn't long before I couldn't deny it anymore and had to look into it. Islam answered ALL of my questions Alhamdulillah, questions that Christianity and other religions just couldn't answer or give me a valid reason for. I reverted exactly 2 monthes ago today and I began seriously looking into Islam about 3/4 monthes previous. My friends and family has been very supportive even though I thought I would be disowned and ditched, etc.
I must say it hasn't been the easiest 2 months of my life, I have had to give up many things and change so much and I'm still in the process of changing. I have also had to learn alot of stuff too but embracing Islam is the best decision I have ever made, I have left behind so much to submit to God and the feeling you get of being close to God in submission is the greatest feeling in the world, nothing can come close to it.
You are very young and I, also like the other people on here respect you as Islam is serious, there is no joking or messing around in Islam, it's about total submission to the One Creator. I'm 18 and was 17 when I discovered Islam which was good because I had left school and could concentrate on it, but I don't want you to feel you are too young for Islam because Islam is Universal, no one is too old, young, or anything to embrace the Truth.
I strongly advise you keep looking into Islam and also visit a Mosque if you can and talk with some of the sisters there, they should be able to give you some advice and help you out.
May Allah (SWT) guide you to the Straight Path and make things easy for you, ameen.
Brother Yusuf.