compound, complex, compund complex

I was wondering if anyone could explain these terms to me? What is a compound sentence, complex sentence, and compound complex sentence. I have a quiz on it tomorrow and I am still very confused about the difference between them and how to tell by looking at it, which one the sentence is.

okay here is a simple sentence
I went to the store.

A compound sentence is joining two simple sentences together or two independent clauses joined by a coordinator. The coordinators are as follows: for, and, nor, but, or, yet, so.

So using the sentence above:
I went to the store,so john decided to go play football with friends.
Here are more examples:

A. I tried to speak Spanish, and my friend tried to speak English.
B. Alejandro played football, so Maria went shopping.
C. Alejandro played football, for Maria went shopping.

You are taking two statement that could be a sentence by themselve and joining them together.
Except for very short sentences, coordinators are always preceded by a comma.

Now Complex senteces are independent clause joined by one or more dependent clauses.
Example:
A. When he handed in his homework, he forgot to give the teacher the last page.
B. The teacher returned the homework after she noticed the error.
C. The students are studying because they have a test tomorrow.
D. After they finished studying, Juan and Maria went to the movies.
E. Juan and Maria went to the movies after they finished studying.

Here you are joining a complete sentence with and incomplete sentece. Let's look at Example C: After they finished studying(sentence fragment, there is no subject,) Juan and Maria went to the Movie( this is a complete sentence)

So a complex sentence is combining a sentence fragment or dependent clause( it is depending on the complete sentence)with a independent clause or complete sentence(a sentence that can stand all by itself).

OK thank you, do you know what a compound complex sentence is?

Also I am confused about the examples for compound sentence. It says, "So maria went shopping," that clause should be able to stand on it's own.. (because a compound sentence is 2 independent clauses that can each stand alone, right?) But it doesn't make sense to read "So Maria went shopping" on it's own.

Just read that part as Maria went shopping and it makes sense and stands alone.
A sentence with at least two independent clauses and one or more dependent clauses (which can also be called subordinate clause) is referred to as a complex-compound sentence.

Ohh okay, that sounds pretty simple. Thank you!