Is it too late? (no negative comments)

Hi there, I wanted to jump on here and ask a quick question. I wanted to see if I could truly change my mind and body to learn to be really good at tennis with consistent training and good training at that. I wanted to start playing when I was younger (7-8), but my parents didn't let me. I'm 15 years old now. I hate to think that even at the age of 15, my opportunities for who I want to become are decreasing. My friend who has been playing for a while says it's also a mental thing, but I don't know. Can I actually learn? I truly am stuck between even trying because I know if I gave up, I'll regret it. I want to go to tournaments and win. I want to be really good. You can say that's not possible, or going to be very hard but please don't say something like ' are you serious lmao' bc ik ppl like to be rude. thanks! I'm a female, I'm left handed and I'm already pretty athletic & strong.