C’est pas mal en général ;)
Jte remets le texte en corrigeant les fautes:
Hey! Today I’m gonna present you a young boy named... , but you can call him X.
He is an eco-activist and began/started to show interest/to get interested in ecology at six, when he watched a documentary about protecting the planet. After that, he delivered his first speech to an ecological demonstration.
A few years later, he participated in/to the COP 21 environment in Paris.
To X, the most important/worst issue in today’s world is the climate. He was the youngest person to speak up to the United Nation about this issue/the climate.
With his crew, the Earth Guardians, they helped their local environment.
X then grew up respecting nature with his siblings/brothers and sisters.
... is also a rock singer, one of his most popular songs is “Young”. He’s now 20 (years old) and he’s always involved/he always gets involved in green actions.
Voilà:) j’espère que ça t’aura aidé.e
