Great question. No matter what type of instrument you play or style of music you are creating/composing, social media is a great way to start by getting others to experience, enjoy and listen to your music.
Tik Tok and Instagram are two great platforms where musicians are able to showcase their creative and unique styles and get others to follow their accounts.
In my personal experience, these platforms are where you can start gaining followers. It's pretty easy to set up an account and then you can start recording your music and tagging it with relevant keywords/hashtags like upcomingartist or newmusic.
On the other side of things, if you are comfortable with it (and check with your parents first) open mics are a great way to gain an audience and an ear to your music. You can try searching "open mics near me" on Google or in Facebook and that could help get you started.
Hope this helps!
Also a big part of being heard is hearing others. Be an active listener, if you nod and really participate when other people are talking to you, it will be easier for them to do the same when its your turn. You will also be able to relate what they're saying to themes in your own life.
Below are a few suggestions :
1. Take videos to put it onto YouTube
2. Would you consider to do busking on the street?
3. Join the music society in your school. They may organize concerts from time to time.
4. Participate music competitions
5. Explore any music groups or bands that playing similar music types. You may leverage some performance opportunities with them.
Hope this helps! Good Luck!