It looks like you're practicing writing sentences, possibly for English grammar or language exam preparation. Let's go through your sentences and correct any grammatical errors:
I’ve got a red pen and a green pen. The red pen is on my desk, and the green pen is in my pencil case.
We’ve got some exams: one is in maths, a second is in history, and a third is in science.
My mom has an orange Fiat, and my dad has an orange Fiat. My dad also has a blue Renault. The Fiat is new, but the Renault is very old.
I’ve got some CDs and some DVDs, but I can’t play the DVDs because my DVD player is broken.
We’ve got a car, a dog, and a mouse. The cat’s name is Sooty, and the dog’s name is Freddy.
If you want to practice more or need help with other topics, let me know!