私の犬

犬が二ひき人います。私の犬は黒いです。小さいのと大きいのが木でいます！ 

I have two dogs. My dogs are black. They are small and big!

(a bit more natural to say: 私は犬を二ひきかっています。(HAVE also means かう[飼う]) 二ひきとも黒いです。一ぴきは小さくて、もう一ぴきは大きいです。)

Good job as always. In this case, we can add more words to make the sentences natural in Japanese. I hope this helps you and if you have any questions, please tell me.