Hey,
You could enter writing competitions. There's a lot out there, and some that are to do with politics, too. Some examples include the Young Science Writer of the Year Award, the Young Poets Religious Poetry Competition, Never Such Innocence, the Orwell Youth Prize, the BBC Young Writers' Award, the Henrietta Branford Writing Competition, and the Think Essay Prize.
These are just some that have interested me, and so I remember them off of the top of my head. If you just search for writing/essay competitions (for Year 10s) on Google/Chrome, you'll get lots of great results.
If you're you haven't already, join your school's debate club and/or model UN. If your school doesn't have these, then I'd recommend talking to a teacher and getting them set up. You could even help run them, which would look even better as an extracurricular.
Another thing you could look into is free online courses. You could do them in debating, politics, writing, and moral issues. Another way to learn more about these would be to read books, listen to podcasts, and watch videos and documentaries about them. And for politics, the best way to learn about it is to read and watch the news.
Again, if your school has one, you could join the school newspaper, or you could even find an online magazine to write for.
If you become interested in finding work experience, you could contact your local newspapers and ask to get experience with them/ shadow a journalist. You could also ask local bookshops and publishing companies for work experience as that relates to writing.
I hope this helps, and if you have any more questions, feel free to ask me. 😊