I know no one can answer this for sure, but I’d like to hear thoughts.
Right now I’m a junior in HS and I really want to apply to NYU Tisch next year. But it’s so competitive that I feel like I have no chances of getting in. Academically, I’m not worried - as of February I had a 5.0 weighted GPA and that’s probably gone up as I’ve gotten a 99 in an AP class since then. But I’m worried that my artistic review won’t be good enough. As of right now, I’ve done costumes and sets for one school show and right now I’m starting props manager and stage manager for another. I’ve taken one technical theatre course and plan on applying to another at the local Fine Arts school next year. Hopefully I’ll be able to tech the school’s spring show and maybe a community theatre show or two between now and the time I’d apply to Tisch, and have at least one technical theatre class (and hopefully be in another when I apply) under my belt. But I know there are people who have been doing this for years so that still doesn’t feel like very much. 
I have no idea how much experience other applicants will have and only a few students get into Tisch.
My S is a senior and applied to Tisch for Production & Design, we got notified via email yesterday that he is waitlisted. If your grades are in line with what NYU expects (looks like academically you should be fine) then it doesn’t matter how much experience you have, they look for potential and leadership. Put everything theater and design/art related on your resume. Be able to talk about your design work confidently, start putting together examples of your work now. The interview/portfolio review is a one on one with the Director of the program and he was very nice. Also, my S got a late start in this as well. Only became interested as a sophomore in high school so he only did the shows in school and maybe 4 shows outside of school. He is going for set design for college but worked on school shows as a stage manager, stage crew, lighting tech, asst building manager, art director, designed and built sets and props, He also was cast in minor roles and ensemble for his school’s musicals and plays. This was just some of the theater-related stuff he did. Tisch only accepts about 10-15 freshman in the P&D studio each year so it is very highly competitive but you have a chance so go for it! Hope this helped. Good luck!