You can search Baidu for "12-year-old China French horn teenager Ceng Yun". At the age of twelve, you can get a reward. Eight or nine years old, even if you don't start learning French horn, you should start music training.

Of course, you can learn French horn at the age of eight, but since you are young, you can learn keyboard instruments+solfeggio for one or two years, and then it will be much easier to learn French horn, and your musical literacy will be much higher than that of simply learning musical instruments.