Are the greek gods and goddesses real?

If you believe so. It's an ancient belief, stemming from thousands of years. I personally feel like it's nothing more than myth, but you do you! Considering that you haven't read other sources, I recommend you check the original sources. Rick Riordan has tweaked many things in his books. You're also incredibly young to decide on this, but I really can't talk, because I am, after all, two years younger than you! (; - o -)

Personally I don't believe in Greek gods and goddesses BUT that's just my opinion, everybody has their own beliefs. We can't really guarantee any of the religions are true but we do have proof that there was at least a god, it's your choice on if you think they are real or not.

According to a couple of vids on youtube, my greek father is Apollo and my greek mother is Athena. I do believe that greek gods and goddesses are real.

God is not a statue, God is not a saint, God is not a picture that any human being can paint. God is a power. The sun, the moon, the stars, the birds, the animals, the flowers, you and me - we all appear to be but in reality, we are all God that manifests as us. It means we appear to be as these but actually, we are God. Just like a plate, a cup, a statue look different but in reality they are all made of clay, everything is clay, similarly, in this world everything is God. God is not just Gods of the Greek mythology, God is everybody, God is everywhere.