We already know that because is subordinating conjunction.
That means function of because is to join two clauses and is followed by verb and subject.
Examples
We could go out for a walk because it’s beautiful weather.
I make this cake because I like it.
Because can come before or after the main clause.
Examples
We went at holiday because it was time to do so.
Because of is a two-word preposition. Because of is usually used before a noun or a pronoun.
Examples
We couldn’t go out because of TV program, it was Star Wars day.
I did it because of my new job.
