First of all, I’m pretty impressed with the OP. My little sister turned 15 today and I only hope she exercises the same stack of morals as you.
I’m 19 years old, 20 in 2 weeks, and I have been dating my boyfriend since I was 16, so a little more than 3 years. When we started dating, he was Catholic and I was “unsure” as to what branch of Christianity I believed it. Being with him has really helped bring me to the Catholic church and I’m in RCIA now to go through the whole process on Easter

My biggest piece of advice would be to be really careful with your sexuality. It’s one thing to have pure intentions, but it’s quite another to find yourself in that “heat of the moment”. Definitely try to avoid that. Living in a courtship has the potential to really help you understand love as the Church sees it, and practicing chastity really helps make real Jesus’ pure love for us.
A really good book to read is “If You Really Loved Me”, by Jason and Chrystalina Evert- they’re amazing. They really make it obvious that chastity is a gift, instead of just a set of rules to follow. They also discuss other aspects of dating relationships outside of just sexuality. Good luck