Ich bin Mora. Ich bin Mora.

Alternatively you could say "Mein Name ist Mora." Or you could combine this sentence with the next one: "Mein Name ist Mora und ich bin zwanzig Jahre alt."

Ich bin 20zwanzig Jahre alt. Ich bin zwanzig Jahre alt.

Ideally numbers should be put in words, otherwise they disrupt the flow of the text.

Ich komme aus Amerika. Ich komme aus Amerika.

Careful: While in English when you say "I'm from America" the default assumption is that you're from the USA, in Germany it could happen that people ask you from which country in the Americas you hail. To remove ambiguity you could say "Ich komme aus den USA" instead.