Sentences

In writing I have been learning about sentences. I have learnt how to write a simple and a compound sentence. A sentence must have a capital letter and a full stops. It must have nouns.
A compound sentence is when you joined a two sentence into one sentence with the word " and ".

Reige There was three astronaut riding in a car is on the Moon. There was three astronaut riding in a car is on the Moon and they saw a red spaceship while there riding around the moon.

This is anther one of my work.

Reige There was two children riding their bike in the beach. There was two children riding their bike in the beach and there having a race with their blue bikes.