こんにちは。わ. bれあんな"Breanna"デッ --> わたしはブリアナです。

こんにちは!わたしシはわ ねこタチがだいスすきです!

*Hello / Good afternoon = こんにちは (type: konnnichiha)

*Katakana is generally used for the words and names from overseas, so we use hiragana for Japanese words. If you haven't know hiragana and katakana, please learn them first to study Japanese. 

*The particle which comes after the subject is は but it's pronounced わ. The same happens for こんにちは and こんばんは, they are pronounced こんにちわ and こんばんわ.

*We don't distinguish singlar and plural very often, in this case, we don't use plural for "I like cats".  

Good job! Please enjoy learning. I hope this helps you. 

こにちわ. bれあんな"Breanna"デッ こんにちは。ブリアナーです。

こにち!わたシわ ねこタチ だいスき! こんにちは！私は、猫が大好きです。

Try not to mix hiragana and katakana.