A simple sentence contains one independent clause, a compound sentence contains 2 independent clauses, and a complex sentence contains one independent clause and one dependent clause.
An example of a simple sentence to describe your morning routine could be:
I wake up an hour before school.
An example of a compound sentence could be:
I usually eat cereal for breakfast, but sometimes I eat toast instead.
An example of a complex sentence is:
After I eat breakfast, I get dressed.
