Hey ive started yr 12 as well. i think you should definitely start by looking through newspapers and finding articles that interest you. Or you can start by doing a mind map. Write down broad topics like gender roles or feminism, write your likes/ dislikes, interests/ disinterests and hopefully you can get a question out of it e.g Why is feminism declining?
You could also do something personal about your own culture if you wanted something original. I'm still searching too!
hope this helped!