Me - is this correct?

わたしはわMoです。 

わたしはわLondonからきました。

"I'm from" has several menings in Japanese. If you are in Japan now, what you wrote is correct, it means like "I came from London". If you are in London now and use it to talk about your nationality, it needs to be said わたしはLondonしゅっしんです(I was born in London.), わたしはLondonにすんでいます(I live in London.) or わたしはいぎりすじんです(I'm English.) 

*generally, we write London(ロンドン) England(イギリス) and your name Mo(モー) with katakana, but if you haven't learned them yet, you can write them in hiragana. 

わたしはわ３７さいです。
にほんごとすしがすきです。

*We use the partcle は after the subject and it is pronounced わ(WA). We also write こんにちは and こんばんは though they are pronounced こんにちわ/ こんばんわ. 

Good job! Please keep up little by little. I hope this was helpful.