The only capitalization mistake in this passage is "after." This word needs to be capitalized because it is the first word in the sentence. The first word of a text should always be capitalized. "Ron Weasley" is correctly written in capitals, because this is a proper name, and proper names also need to be written in capital letters at all times. The rest of the nouns in the passage are common nouns, and therefore, do not have to be capitalized.
<span>"After" should be capitalized, as it begins the sentence. "Ron Weasley" is properly capitalized because a name contains proper nouns. "Stadium" does not have to be capitalized because the official name is not listed--if it were a specific stadium, it would have to be capitalized, but in this case the capitalization is correct. </span>
The salutation is to greet the person you are addressing, it goes before the introduction. The introduction is a brief summary of the letter itself and the body is the letter itself.
