Punctuation with conjunctions.

I'm learning English punctuation,and I would really like you to tell me if the following concepts are correct.

1 An independent clause is a complete thought and can stand on its own.two or more independent clauses are normally joined by "coordinating conjunctions" to form compound sentences. A comma should always be placed before the coordinating conjunction.

2 A dependent clause can't stand on its own because it's not a complete thought. One or more dependent clauses are combined with an independent clause to form a "complex sentence". When the dependent clause appears at the beginning, a comma must be placed at the end of the clause. If the independent clause appears first, a comma is not needed at all.

3 There can be either a simple predicate or a compound predicate. The compound predicate omits the second subject of the sentence but always refers to the same subject. No comma is needed in a compound predicate,but we must use commas when we have to separate a list of things.

Based on those concepts,are the following sentences correct?

"Simple sentences"

1 I love football.

2 We need money.

"Compound sentences"

1 I like chocolate but,I really hate sweets.

2 We need the money really badly,but we won't ask for a loan.

"Complex sentence"

1 If you use proper punctuation, your writing becomes more interesting.

2 I'm willing to help her although she has always been very rude to me.

"Compound predicate"

1 We danced all night and met new people.

2 They were watching football and eating pizza.

3 We went shopping,bought some clothes, visited my mother, played tennis,and went to the beauty shop !

The last comma is called "oxford comma" right?