Hello Beth, All of the four sentence have a correct sentence structures, very good. But please note that جذاب is a not very accurate to be used in this context as a translation of cute, since it actually means attractive. Instead , use جميل which is a literal translation for beautiful but it means also cute, and if you write in the Egyptian dialect, then you will get to use word like عسول which mean honey-like, and used to describe a physical and personal character, as well as the word cute it self is a common word used in Egypt, fortunately it pronounced the same way in English and means also the same. Also it is important to learn how to write names in Arabic, your name is بيث , your sons are باتريك و كونور and your dog's name is ناكلز. The last point, you can completely ignore it since you will learn it any way in the future, is that كويس is not an stander Arabic word, rather it is an Egyptian dialect and it does mean nice or fine, and it is one of the daily essential Egyptian vocabs, بيته is both stander and Egyptian, but they are pronounce slightly different according what dialect are you using , the way you write بيته is actually in Stander Arabic and the word كويس is an Egyptian word, so the sentence was unnatural to a native speaker. I hope that I didn't confuse you with my explanation, and I am really sorry if I did, please feel very to ask about any information was not clear, or anything you want to know in general. Keep learning and have a wonderful day.

(His house is nice) بيته كويس i would like to turn your attention for the translated of this word (كويس ), this word is using in dialect egyptian language , and i suggest to use (جميل او لطيف ) instead of (كويس it will be more accurate as per arabic standard.

إسم كلبي

(My dog's name is Knuckles) كلبي إسمه نيكولاس او إسم كلبي نيكولاس -the other sentences is right

yes this correct but you forrget the ى letter يسمى كلبى*